Videophone calls (also: videocalls and video chat), differ from videoconferencing in that they expect to serve individuals, not groups. However that distinction has become increasingly blurred with technology improvements such as increased bandwidth and sophisticatedsoftware clients that can allow for multiple parties on a call. In general everyday usage the term videoconferencing is now frequently used instead of videocall for point-to-point calls between two units. Both videophone calls and videoconferencing are also now commonly referred to as a video link.

Webcams are popular, relatively low cost devices which can provide live video and audio streams via personal computers, and can be used with many software clients for both video calls and videoconferencing.

A videoconference system is generally higher cost than a videophone and deploys greater capabilities. A videoconference (also known as avideoteleconference) allows two or more locations to communicate via live, simultaneous two-way video and audio transmissions. This is often accomplished by the use of a multipoint control unit (a centralized distribution and call management system) or by a similar non-centralized multipoint capability embedded in each videoconferencing unit. Again, technology improvements have circumvented traditional definitions by allowing multiple party videoconferencing via web-based applications.A separate webpage article is devoted tovideoconferencing.

A telepresence system is a high-end videoconferencing system and service usually employed by enterprise-level corporate offices. Telepresence conference rooms use state-of-the art room designs, video cameras, displays, sound-systems and processors, coupled with high-to-very-high capacity bandwidth transmissions.

Typical uses of the various technologies described above include videocalling or videoconferencing on a one-to-one, one-to-many or many-to-many basis for personal, business, educational, deaf Video Relay Service and tele-medical, diagnostic and rehabilitative use or services. New services utilizing videocalling and videoconferencing, such as personal videocalls to inmates incarcerated in penitentiaries, and videoconferencing to resolve airline engineering issues at maintenance facilities, are being created or evolving on an on-going basis.

21st century improvements

Significant improvements in video call quality of service for the deaf occurred in the United States in 2003 when Sorenson Media Inc. (formerly Sorenson Vision Inc.), a video compression software coding company, developed its VP-100 model stand-alone videophone specifically for the deaf community. It was designed to output its video to the user's television in order to lower the cost of acquisition, and to offer remote control and a powerful video compression codec for unequaled video quality and ease of use with video relay services. Favourable reviews quickly led to its popular usage at educational facilities for the deaf, and from there to the greater deaf community.

Coupled with similar high-quality videophones introduced by other electronics manufacturers, the availability of high speed Internet, andsponsored video relay services authorized by the U.S. Federal Communications Commission in 2002, VRS services for the deaf underwent rapid growth in that country.

Present day usage

Using such video equipment in the present day, the deaf, hard-of-hearing and speech-impaired can communicate between themselves and with hearing individuals using sign language. The United States and several other countries compensate companies to provide 'Video Relay Services' (VRS). Telecommunication equipment can be used to talk to others via a sign language interpreter, who uses a conventional telephone at the same time to communicate with the deaf person's party. Video equipment is also used to do on-site sign language translation via Video Remote Interpreting (VRI). The relative low cost and widespread availability of 3G mobile phonetechnology with video calling capabilities have given deaf and speech-impaired users a greater ability to communicate with the same ease as others. Some wireless operators have even started free sign language gateways.

Sign language interpretation services via VRS or by VRI are useful in the present-day where one of the parties is deaf, hard-of-hearing or speech-impaired (mute). In such cases the interpretation flow is normally within the same principal language, such as French Sign Language (LSF) to spoken French, Spanish Sign Language (LSE) to spoken Spanish, British Sign Language (BSL) to spoken English, and American Sign Language (ASL) also to spoken English (since BSL and ASL are completely distinct to each other), and so on.

With video interpreting, sign language interpreters work remotely with live video and audio feeds, so that the interpreter can see the deaf or mute party, and converse with the hearing party, and vice versa. Much like telephone interpreting, video interpreting can be used for situations in which no on-site interpreters are available. However, video interpreting cannot be used for situations in which all parties are speaking via telephone alone. VRS and VRI interpretation requires all parties to have the necessary equipment. Some advanced equipment enables interpreters to control the video camera remotely, in order to zoom in and out or to point the camera toward the party that is signing.Multilingual sign language interpreters, who can also translate as well across principal languages (such as to and from SSL, to and from spoken English), are also available, albeit less frequently. Such activities involve considerable effort on the part of the translator, since sign languages are distinct natural languages with their own construction, semantics and syntax, different from the aural version of the same principal language.

Technology

Webcams typically include a lens, an image sensor, and some support electronics, and may also include a microphone for sound. Various lenses are available, the most common in consumer-grade webcams being a plastic lens that can be screwed in and out to set the camera's focus. Fixed focus lenses, which have no provision for adjustment, are also available. As a camera system's depth of field is greater for small image formats and is greater for lenses with a large f-number (small aperture), the systems used in webcams have a sufficiently large depth of field that the use of a fixed focus lens does not impact image sharpness to a great extent.

Image sensors can be CMOS or CCD, the former being dominant for low-cost cameras, but CCD cameras do not necessarily outperform CMOS-based cameras in the low cost price range. Most consumer webcams are capable of providing VGA-resolution video at a frame rate of 30 frames per second. Many newer devices can produce video in multi-megapixel resolutions, and a few can run at high frame rates such as the PlayStation Eye, which can produce 320×240 video at 120 frames per second.

Support electronics are present to read the image from the sensor and transmit it to the host computer. The camera pictured to the right, for example, uses a Sonix SN9C101 to transmit its image over USB. Some cameras, such as mobile phone cameras, use a CMOS sensor with supporting electronics "on die", i.e. the sensor and the support electronics are built on a singlesilicon chip to save space and manufacturing costs. Most webcams feature built-in microphonesto make video calling and videoconferencing more convenient.

The USB video device class (UVC) specification allows for interconnectivity of webcams to computers even without proprietary drivers installed. Microsoft Windows XP SP2, Linux andMac OS X (since October 2005) have UVC drivers built in and do not require extra drivers, although they are often installed in order to add additional features.

Uses

Childcare Webcasting (Video Monitoring)

Childcare webcams cater to a growing demand for improved security, communications, and increased service value in daycare facilities across the country. No longer are webcams just a trend; they are quickly becoming an industry standard. According to researchers and industry leaders, as many as 100 childcare facilities add Internet viewing systems each month and that the total number of centers with some form of Internet monitoring runs into several thousands. In the United States, services such as Peanut Butter and Jelly TV have been offering premier webcasting systems to centers nationwide for many years.

Videocalling and conferencing

As webcam capabilities have been added to instant messaging, text chat services such as AOL Instant Messenger, and VoIP services such as Skype, one-to-one live video communication over the Internet has now reached millions of mainstream PC users worldwide. Improved video quality has helped webcams encroach on traditional video conferencing systems. New features such as automatic lighting controls, real-time enhancements (retouching, wrinkle smoothing and vertical stretch), automatic face tracking and autofocus assist users by providing substantial ease-of-use, further increasing the popularity of webcams.

Webcam features and performance can vary by program, computer operating system, and also by the computer's processor capabilities. For example, 'high-quality video' is principally available to users of certain Logitech webcams if their computers have dual-core processors meeting certain specifications. Video calling support has also been added to several popular instant messaging programs.

Video security

Webcams are also used as security cameras. Software is available to allow PC-connected cameras to watch for movement and sound,recording both when they are detected; these recordings can then be saved to the computer, e-mailed or uploaded to the Internet. In one well-publicised case,a computer e-mailed out images as the burglar who stole it, allowing the owner to give police a clear picture of the burglar's face even after the computer had been stolen.

Recently webcam privacy software has been introduced by such companies such as Stop Being Watched. The software exposes access to a webcam and prompts the user to allow or deny access by showing what program is trying to access the webcam. Allowing the user to accept a trusted program the user recognizes or terminate the attempt immediately. Other companies on the market manufacture and sell sliding lens covers that allow users to retrofit the computer and close access to the camera lens.

Video clips and stills

Webcams can be used to take video clips and still pictures. Various software tools in wide use can be employed for this, such as PicMaster(for use with Windows operating systems), Photo Booth (Mac), or Cheese (with Unix systems).

Later developments

One of the most widely reported-on webcam sites was JenniCam, created in 1996, which allowed Internet users to observe the life of its namesake constantly, in the same vein as the reality TV series Big Brother, launched four years later. More recently, the website Justin.tvhas shown a continuous video and audio stream from a mobile camera mounted on the head of the site's star. Other cameras are mounted overlooking bridges, public squares, and other public places, their output made available on a public web page in accordance with the original concept of a "webcam". Aggregator websites have also been created, providing thousands of live video streams or up-to-date still pictures, allowing users to find live video streams based on location or other criteria.

Around the turn of the 21st century, computer hardware manufacturers began building webcams directly into laptop and desktop screens, thus eliminating the need to use an external USB or Firewire camera. Gradually webcams came to be used more for telecommunication, orvideotelephony, between two people, or among a few people, than for offering a view on a Web page to an unknown public.

The term 'webcam' may also be used in its original sense of a video camera connected to the Web continuously for an indefinite time, rather than for a particular session, generally supplying a view for anyone who visits its web page over the Internet. Some of them, for example those used as online traffic cameras, are expensive, rugged professional video cameras.

For less than $100 US (retail), Minoru makes a 3D webcam which produces videos and photos in 3D Anaglyph image with a resolution up to 1280x480 pixels. Both sender and receiver of the images must use 3D glasses to see the effect of three dimensional image.

Connectix QuickCam

The first known commercial webcam, the QuickCam, entered the marketplace in 1994, created by the U.S. computer hardware and software company Connectix, which later sold its product line to another U.S. company, Logitech, in 1998. QuickCam was originally the design of Jon Garber, who wanted to call it the 'Mac-camera', but was vetoed by Connectix's marketing department which saw the possibility of it one day becoming a cross-platform product. It was to become Connectix's first Microsoft Windows product 14 months later when QuickCam for Windows was launched in October 1995. The Macintosh QuickCam had shipped earlier in August 1994, and could only provide 320 x 240 pixel resolution with a grayscale colour depth of 16 shades at 60 frames per second, which would drop down to 15 frames per second if it was switched to a less basic 256 shades of gray (8-bit).^[5]

The QuickCam had earlier started as a graduate degree research project in the early 1990's between various California and East Coast universities, and was originally designed with an RS-232 serial port connector color CCD camera. Both the Apple and Windows software versions were sponsored by DARPA and the U.S. Department of Veterans Affairs. The Windows software version was compiled under bothMS Visual Studios and Borland C/C++ compilers for both Windows 3.11 and Windows 95. Videoconferencing via computers already existed, and at the time client-server based videoconferencing software such as CU-SeeMe had started to become popular.

The initial QuickCam model was available only for the Apple Macintosh, connecting to it via its serial port, and was sold at a cost of $100. In 2010, Time Magazine designated QuickCam as one of the top computer devices of all time.

Webcam

A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.

Their most popular use is the establishment of video links, permitting computers to act asvideophones or videoconference stations. This common use as a video camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance andcomputer vision and there are also uses on sites like video broadcasting services and for recording social videos .

Webcams are known for their low manufacturing cost and flexibility, making them the lowest cost form of videotelephony. They have also become a source of security and privacy issues, as some built-in webcams can be remotely activated via spyware.

Windows Desktop

After your computer finishes loading windows into memory, you arrive at a screen knows as the windows desktop. The desktop is the workspace, the surface on which you spread out any file folders, programs and documents you want to use. Technically, the desktop is the area behind all the objects on the screen, inculding any windows that you open. No matter what you do in the windows environment, you can always get back to the desktop even if you open an application program and expand it to fill the whole screen. Below the desktop you will most likely see a gray bar knows as the taskbar which will be discussed later.

A typical windows 98 desktop is populated with the little labeled pictures knows as icons. When you double click a icon, you open it uop into the rectangular frame called a window. The icos that appear on you desktop when you start windows provide quick access to the places on your compuer that you visit most often. Desktop contains various types of icons.

Folder icons

Folder icnos open into folder windows which reveal the contents of particular folders in your computerrized filing system.

Program Icons

Program icons open into applicaion programs, that is they load the associated programs into memory and start them running.

Document icons

Document icons open into documents. When you double click a document icon, windows starts the application (word processing program, Spreadsheet,database, or whatever) in which the document was created and then opens the document itself.

Shortcut Icons

Shortcut icons provide alternative entry ways to programs, documents and folders. Shortcut icons always have arrows on them and their lables frequently contain the words.

Multitasking

Windwos not only allows you to open two or more programs at once, it allows you to carry out work in both programs simultaneously. If you need to perform a time consuming task  in one program such as, copying a large file from the internet, you simply start the process and then swithc to a different program. The first task will continue unattended while you work in the second. This capability to work on two or more things at once is called multitasking. People perform multitask all the time, such as, reading while watching  television, talking on the phone while cooking dinner, chewing gum while jogging, etc.

Windows Clipboard

Windows also includes a feature knows as the clipboard that lets you easily copy or more data from one program to another and you can do this using hte sam cut, copy and past commands in almost all windows programs. This means that you can copy those sales figures directly from your spreadsheet into your word processing document without having to use any special importing or exporting commands.

Important Features of Windows

Running Several Programs Simultaneously

Windows also allow you to run multiple programs at once. If you are just getting started with computer, this feature may seem of limited value. Why should you want to run two programs at once when you are still feeling overwhelmed by the first one? After you get a little more comfortable with your system, however, you may find this feature useful.

Switching Between open Applications

Imagine getting a phone call about your latest sales firgures when you are in the middle of typing a letter in your word processing program. If you are using windows, you can easily open your spreadsheet program and fintd the necessary information without leaving your word processing program.When you are done, a single mouse click or keystroke will take you back to your word processing document and you can pick up exctly wher you left off.

Issues in Data Management

Data Entry
Data Updates
Data integrity
Data security
Data accessibility

Data Entry

New titles are added every day
New customers are being added every day
Some of the above may require manual entry of new data into the computer systems
That can be achieved, for one, by user-interfaces that prevent the input of invalid data

Data Updates

Old titles are deleted on a regular basis
Inventory changes every instant
Bookd prices change
Shipping cost change
Customers perosnal data chage
Various discoutn schemes are always commencing and concluding
All those actions require updates to existing data

Data Security

All the data that Bholibooks has in its computer systems in quite critical to its operation
The security of the customers personal data is of utmost improtance. Hackers are always looking for that type of data, espically for credit card numbers
Enough leaks of that type and customers will stop doing busness with Bholibooks.

Data Integrity

Integrity refers to maintaing the correctness and consistencey of the data
Correctness free from errors
Consistencey no conflict among related data items
Integrity can be compromised in many ways
Typing errors
Transmission errors
Hareware malfunctions
Program bugs
Viruses
Fire, flood etc.

Data Accessibility

If the transaction and inventory data is placed in a disorganized fashion on a hard disk, it becomes very diffucult to later search for a stored data item
What is required is that
Data be stored in an organized manner
Additional info about hte data be storedso that the data access times are minimized.

BholiBooks

Consider the situation of a large, online bookstore
They have an inventory of millions of books, with new titles constantly arriving, and old ones being phased out on a regular basis
The price for a book is not a static feature it varies every once in a while
Thousands of books are shipped each day, changing the inventory constantly
Some are returned aganin changing the inventory situation constantly
The cost of each shipped order depends on
Pricess of individual books
Size of the order
Location of the customer
Mode of shipment
For each order the customer's particulars name address phone number credit card number are required.

Data Management

We looked at the distinguishing features of intelligent systems w.r.t other software systems.
We looked at the role of intelligent sytems in scientific, business, consumer and other applications.

(Artificial) Intelligent Systems

SW programs or SW/HW systems designed to perform complex tasks employing strategies that mumic some aspect of human thought.

Not a suitable Hammer for All Nails!

if the nature of computations required in a task is not well understood or there are too many exceptions to the rules or known algorithms are too complex or inefficient then AI has the potential of offering an acceptable solution

Selected Applications

Games Chess, Simcity
Image recognition
Medical diagnosis
Robots
Business intelligence

Neural Networks

Original inspiration was the human brain emphasis now on usefulness as a computational tool.

Genetic Algorithms

Based Drawin's evolutionary principle of survivial of the fittest
GAs require the ability to recognize a good solution, but not how to get to that solution

Who is Computing Professional?

Professionals involded in the development and or maintenance of SW and or computer HW
Computer scientists software engineers computer engineers and some of the relecom engineers are engerally classified as computing professionals.

Todays Focus Group

Due to the limitation on time today we will be foucsing only on a subset of computing professionals those involded in the development of SW.
Let us further restrict discussion to computing professionals belonging to an organization foucsed solely on custom SW development
They work in a 100 person organization pretty big on a local scale but quite insignificant on an international one.

Development Team

the number of development teams has varied between 3-7 at this organization.
Team size has varied between 3-35.
Large teams are organized as a collection of sub teams.
Lowest level team Bo more than 7 members.
Responsible for a project from after the specifications stage till the very end.

Project  Manager

Responsibilities
Planning and tracking of the project
Arranging of the appropriate resources
Lient relationship management

Architect

Responsibilites
Technology selection
Highe level design
Make certain that the implementation remains true to the design

Team Lead

Responsibilties
Planning and tracking of the project
Detailed design
Professional development of team members
incase of small teams development activities

Developer

Responsibilities
Module level design
Coding
Unit testing

Executive Team

CEO Chief Executive Officer
Developer of the vision of the organization
Great PR skills
Great knack for spotting talent
COO cheif operating officer
Great organizational and interpersonal skills
CMSO Chief Marketing and Sale Officer
Responsibilites for bringing in work
Innovative

The Computing Profession

Today we discuss on the impact of computing on
Business
Work
Living
Health
Education
Why should we as computing professionals, be interested in studying the social implications of our creations?
computing technology has changed our way of life linke on other technology.
We need to study how ti has done it to highlight the mistakes and success stories of the past.
We need to do ti so that we can learn from them and select our future direction accordingly.

Dilemma of Computing

Are we heading towards a future where the role of the masters and the slaves will be switched?
should we slow down or even reverse some of the technology advances to avoid that dark scenario?

Powerful Global Corporations

Internet based communication is allowwing business entities to coordinate the activities of their globally spread units with greater accuracy
All this has made these busniess entities very powerful evn more powerful thatn many nation states.

The Network Organization

The network paradigm is becoming the preferred organizational structure of more and more organizations as time goes by
This new organization is replacing the old style layered tree structured organizational model.

Working from Home

Computing has make it possible for some to avoid going the office for their work.
They can do their work from home and communicate their ideas, questions, answers to their colleagues throught the internet
This gives them more time to spend with their families due to the time they save on commuting to their place of work.

From Mass to pesonalized Marketing

The Web has changed marketing foreve redirecting ti from a mass focus to a single person focus.

The political process

Throught computer discussion forums newsgroups and  mailing lists public and politicians may engage in a free open exchange of ideas without leaving the comfort of their not so comforatble and very comfortable homes respectively.

Distances Have Contracted

Beacuse of the ever decreasing costs of verbal text video communications, it is becoming easier to stay in touch with anyone, regardless of tehir physical location.

Distance Are increasing

Internet based communication is allowwing business entities to coordinate the activities of their globally spread units with greater accuracy
All this has made these busniess entities very powerful evn more powerful thatn many nation statesSolitude is the order of the day as many children and adults spend their free time surfing, chatting playing computer games instead of spending it on interacting with friends or family.

JavaScript Data Types

Unlike in C,C++ and javaa,There are no explicit  data types in javascript.
Numbers,  eg.23,4.3,-230,4.4e,24
Booleans,  eg.true,false
String,       eg,hello,"what is time?"  
Undefined
We will comebackto these data types,but before that we have to haveto define a few new terms

Variables

Variables  give  us  the ability to  manipulate data through reference instead of actual value.Variables are names assigned to values.
Variables  are containers that hold values.

Declearing Variables

Many languages require that a variable be declared before it is first used.Although Javascript allows variable declaration,it does not require it .Except in the case when we want to declare a variable being localmore on local variables later in the course!.

Declearing Variables
var height.var name,address, phone Number

Javascript Variables are Dynamically Typed


Any variable in javascript can hold any type of value,and that type can changemidway throgh the progam.
This is unlike the case for C,C++ and java,where a variable's type is defiend before usage.
The untyped feature makes Javascript simpler to program in when developing short programs.However,this feature brings in a few problems as well.

JavaScripts Operators.

Operators operates on oprands to achieve the desired results
JavaScript has numerous operators, classified in many categories.We willlook at only a few of thembelonging to the fellowing categories.

Assignment operators
Arithmetic operators
Comparison operators
String operators
Logical operators

Data Types & Operators

Today we are discussing about the  data types and operators
Everything that javascript manipulates, it treats as and object   a window or a button.
An object has properties. a window has size,position,status,etc
An object can be manipulated  with  methods that are associated with that  object a resize a window with resize to (150,200)

Types of Objects

JavaScripts objectes
Objects that are part of javascript
examples.window document

Browser objects
objects that contain info not about the contentsof the display  but the browseritself
Examples history, navigator.
User defined object

Object-Based, Not Object-Oriented

JavaScript is not a true object-oriented language like  C++or Java
Itis so because it lacks two k ey features
A formal inheritance mechanism Strong typing
The Concept of objects and associated properties and  methods is a very powerful idea, and we will be talking about it a lot during this course.
However  today our focus will be on someof the nitty gritty details of javascript.

Device Drivers

A device driver often called a driver for short, is a computer program that is intended to allow another program to interact with a hardware device. Think of a driver as a manual that gives the operating system.
A device driver essentially converts the more general input/output instructions of the operating system to messege that the device type can understand.

Major Types of SW

System software is responsible for dcontrolling integrating, and managing the individual hardware components of a computer system.
System software performs tasks like transferring data from memory to disk. or rendering text onto a display specific kinds of system software include loading programs, operating systems, devices drivers, compilers, assemblers, linkers, and utlities.

Software libraries that perform generic functions also tend to be regarded as system termed firmware. these generally perform the background tasks in a comptuer.
These programs, many times talk directly to the HW.

Language Translators

Human programmers write programs in a language that is easy to understand for them. They use language translators to vonvert that program into machine language. It converts the human understandable code in uPs understandable code. Language that is easy to understand for the uPs.

Machine Language

A system of codes directily understandable by the computer CPU is termed this CPU native or machine language. Although they are in fact two dirrerent types of languages. Machine code is composed only of the two binary digits 0 and 1.
Every CPU has its own machine language, althought there is considerable overlap between some. If CPU a understands the full language of CPU B its is said that A is compatible with B.

Computer Software

Today we are discussing about the computer software.
Discuss about the role of software in computing systems
To learn to differentiate among software belonging to the system and application categories

Software

The set of instructions that operates various parts of the hareware. Also termed as Computer program.

The HW needs SW to be useful the SW needs HE to be useful
When the use needs something done by the computer he .she gives instructions in the form of SW to computer HW.these instructions need to be written in the language that is readily understood by the computer uP.

CD

A compact disc is a small, portable, round medium for electronically recording, storing, and playing back audio, video, text, and other information in digital form.

Tape

In computers, tape is an external storage medium usually both readable and writable, can store data in the form of electromagnetic charges that can be read and also erased.

Floppy disk

A diskette is a random access, removable data storage medium that can be used with personal copters. The term usually refers to the magnetic medium housed in a rigid plastic cartridge measuring 3.5 inches square and about 2 millimeters thick.

Hard Disk

Hard disk is a computer sotrage device which saves and retrieves the data when required. Its capacity is much greater that the computer memory (RAM,ROM) Data on hard disk is stored and retrieved from electromagnetically charged surface.

ROM

ROM is built in computer memory containing data that normally can only be read, not written to ROM contains the programming that allows your computer to be booted up or regenerated each time you turn it on.

Punch Cards

A card on which data can be recorded in the form of punched holes.

RAM

RAM (Random access memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor. RAM is much faster to read from tand write to that the other kinds of storage in a computer the hard disk, floppy disk, and CD-ROM

Memory / Storage

There are many types of Memory / Storage

RAM
Punch Cards
ROM
Hard Disk
Floppy Disk
Tape
CD
DVD

Processor

There are many type of processors

Pentium
Celeron
Athlon
PowerPC
Strong ARM (PDA)
Crusoe (Laptops)
SPARC(Workstations)

What is Port?

On computer and telecommunication devices a port is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind. Typically a personal computer is provided with one or more serial ports and usually one parallel port.

Scanner

A Scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. Scanner come in hand held feed in and flatbed types and for scanning black and white only, or color.

Microphone

A device that converts sound waves into audio signals. These could be used for sound recording as well as voice chatting through internet.

Digital Camera

A Digital camera records and stores photographic images in digital form that can be fed to a computer as the impressions are recorded or stored in the camera for later loading into a computer or printer. currently, Kodak, Canon and several other companies make digital cameras.

Joystick

In Computers, a joystick is a cursor control device used in computers games. The joystick, which got its name from the control stick used by a pilot to control the ailerons and elevators of a airplane, is a hand-held lever that pivots on one end and transmits its coordinates to a computer.

Keyboard

On most computers, a keyboard is the primary text input device. A keyboard on a computer is almost identical to a keyboard on a typewriter. Computer keyboards will typically have extra keys, however. Some of these keys are meant to be used in conjunction with other keys just like shift on a regular typewriter.

Mouse

A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position.

Input Devices

There are many input devices.

Mouse
Keyboard
Joystick
Digital Camera
Microphone
Scanner

Hardware Components

All the computers have the following hardware components

Input
The devices used to give the computer data or commands are called input devices. like keyboard, mouse scanner etc.

Processor

A processor is the logic circuitry that responds to and processes the basic instructions that drive a computer. The  term processor has generally replaced the term central processing unit (CPU).

Memory

Memory is the Electronic holding place for instructions and data that your computer's microprocessor can reach quickly. When your computer is in normal operation, its memory usually contains the main parts of the operating system and some or all of the application programs and related data that are being used.

Storage

Computer Storage is the holding of data in an electromagnetic form for access by a computer processor. It is also called secondary storage. In secondary storage data resides on hard disks. tapes, and other external devices.

Computer Types

There are many types according to capability.

Supercomputers
A Supercomputer is a computer that performs at or near the currently highest operational rate for computer.A Supercomputer is typically used for scientific and engineering applications that must handle very large databases or do a great amount of computation.At any given time, there are usually a few well publicized supercomputers that operate at very latest and always incredible speeds.

Mainframe Computers

A Very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously, in the hierarchy that stars with a simple microprocessor at the bottom and moves to supercomputers at the top, mainframe are just below supercomputers.

Servers / Mainframe Computers

A mid sized computer, In size and power, minicomputers lie between workstations and mainframes.

In the past decade, the distinction between large minicomputers and small mainframes has blurred however, as has the distinction between small minicomputers and workstations.

Desktops

There are also called microcomputers. Low-end desktops are called PC's and high-end one Workstations. There are generally consisting of a single processor only, some times 2, along with MB's of memory, and GB's of storage.

Portables

Portable computer is a personal computer that is designed to be easily transported and relocated, but it is larger and less convenient to transport than a notebook computer. The earliest PC's designed for easy transport were called portables.

World Wide Web

Browser
A browser is an application program that provides a way to look at and interact with all the information on the world wide web. The world browser seems to have originated prior to the web as a generic term for user interfaces that let you browse test files online. By the time the first web browser with graphical user interface was generally available Mosaic, in 1993 the term seemed to apply to web content too.

URL

URL ( Uniform Resource Locator , previously Universal Resource Locator)- pronounced YU-AHR-EHL or in some quarters, UHRL is the address of a file(resource) accessible on the internet. The type of file or resource depends on the internet application protocol.

What is Web Site?

A Web site is a related collection of world wide web files that includes a beginning file called a home page.A company or an individual tells you how to get to their Web site by giving you the address of their home page. From the home page, you can get to all other pages on their site.

Who Invented the Web & Why?

CERN is a meeting place for physicists from all over the world, who collaborate on  complex physics, engineering and information handling projects, Thus, the need for the WWW system arose from the geographical dispersion of large collaborations, and the fast turnover the fellows,students and visiting scientists, Who had to get up the speed on projects and leave a lasting contribution before leaving.

Evolution of Computing

Turning Machine - 1936
Introduced by Alan Turing in 1936, Turing machines are one of the key abstractions used in modem computability theory, the study of what computers can and cannot do.A Turing machine is a particularly simple kind of computer, one whose operations are limited to reading and writing symbols on a tape, or moving alone the tape to the left or right. The tape is marked off into squares, each of which can be filled with at most one symbol.

Vacuum Tube - 1904

Vacuum Tube is just that a glass tube surrounding a vacuum ( an area from which all gases has been removed). What makes it interesting is that when electrical contacts are put on the ends you can get current to flow though that vacuum. A British scientist named Jhon A Fleming made a vacuum tube known today as diode.

ABC - 1939

The Atanasoff-Berry Computer was the world's first electronic digital computer. It was built by Jhon Vincent Atanasoff and Clifford Berry at Lowa State University During 1937-42. It incorporated several major innovations in computing including the use of binary arithmetic, regenerative memory, parallel processing, and separation of memory and computing functions.

Introduction

Charles Babbage (1791-1871)
Creator of the Analytical Engine- the first general-purpose digital computer (1833) The Analytical Engine was not built until 1943 ( in the form of the Harvard Mark I)

The Analytical Engine

A Programmable, mechanical, digital machine Could carryout any calculation could make decisions based upon the results of the previous calculation components: Input, memory, processor, output.

Ada, Countess of Lovelace (1815-52)

Babbage: the father of computing

Ada: the mother

Wrote a program for computing the Bernoulli's sequence on the Analytical Engine world's 1st computer program

Ada:  A programming language specifically designed by the Us Dept of Defense for developing military applications was named Ada to honor her contributions towards computing.