COMPUTER FUNDAMENTAL (SESSION 1 AND 2)

SESSION 1

HARDWARE REFERS TO ALL THE PHYSICAL COMPONENTS OF A COMPUTER. IT INCLUDES ALL INPUT DEVICES, PROCESSING DEVICES, STORAGE DEVICES, AND OUTPUT DEVICES. THE KEYBOARD, MOUSE, MOTHERBOARD, MONITOR, HARD DISK, CABLES, AND PRINTER ARE ALL EXAMPLES OF HARDWARE.

YOU USE HARDWARE TO PROVIDE INPUT TO A COMPUTER AND ALSO TO GET THE DESIRED OUTPUT.

COMPUTER USES PROCESSING DEVICES TO WORK ON THE INPUT DATA AND GENERATE THE DESIRED OUTPUT. THE MOST IMPORTANT PROCESSING DEVICE IS THE CENTRAL PROCESSING UNIT (CPU). THE CPU IS THE BRAIN OF THE COMPUTER. IT PROCESSES THE INPUT TO PERFORM CALCULATIONS AND PRODUCE OUTPUT.

A MOTHERBOARD IS A LARGE CIRCUIT BOARD THAT CONNECTS INPUT, OUTPUT, AND PROCESSING DEVICES. THE MOTHERBOARD CIRCUITS PROVIDE PATHWAYS THAT ALLOW DATA TO PASS THROUGH THESE VARIOUS COMPONENTS. IT ALSO CONTAINS CHIPS THAT DETERMINE HOW, WHEN, AND WHERE DATA CAN FLOW THROUGH THE COMPUTER. ALL OF THESE DEVICES ARE PLUGGED INTO THE MOTHERBOARD.

THE OPERATING SYSTEM PROVIDES AN INTERFACE THAT HELPS YOU TO INTERACT WITH THE COMPUTER. SOME EXAMPLES OF THE OPERATING SYSTEMS ARE WINDOWS, LINUX, AND ANDROID. A USER INTERFACE CAN BE EITHER TEXT-BASED (CUI: - CHARACTER USER INTERFACE) OR GRAPHICS-BASED (GUI: - GRAPHICAL USER INTERFACE). MOST OPERATING SYSTEMS PROVIDE A GRAPHICAL USER INTERFACE (GUI), WHICH DISPLAYS IMAGES AND PICTURES THAT ALLOW YOU TO INTERACT WITH A COMPUTER EASILY.

”ROW FACTS & FIGURES ARE CALLED DATA.”

 EX: - 50, 25, 36.2, RAM, JAY ETC.

“PROCESSED DATA IS CALLED INFORMATION. “

EX: - NAME: - RAM

          AGE: - 25.

PROGRAMS, ALSO CALLED APPLICATIONS, USE THIS PLATFORM TO PERFORM TASKS. THERE ARE MANY TYPES OF PROGRAMS. SOME PROGRAMS ALLOW YOU TO PERFORM TASKS SUCH AS WRITING LETTERS, DOING CALCULATIONS, OR SENDING E-MAIL MESSAGES. FOR EXAMPLE, A WORD PROCESSOR, SUCH AS MICROSOFT OFFICE WORD 2007, IS A PROGRAM THAT HELPS YOU CREATE A LETTER.

PROGRAMS PROCESS DATA THAT YOU PROVIDE AS INPUT TO YOUR COMPUTER. THIS DATA CAN BE IN THE FORM OF TEXT, GRAPHICS, AUDIO, OR VIDEO DEPENDING ON THE TYPE OF PROGRAM. FOR EXAMPLE, CALCULATOR IS A PROGRAM THAT REQUIRES INPUT IN THE FORM OF NUMBERS.

NETWORK: A GROUP OF COMPUTERS AND ASSOCIATED DEVICES THAT ARE LINKED TOGETHER TO FACILITATE SHARING INFORMATION IS CALLED A NETWORK. NETWORKS CAN ALSO BE USED TO SHARE DATA AND DEVICES SUCH AS PRINTERS. YOU CAN ALSO COMMUNICATE WITH OTHER COMPUTER USERS ON THE NETWORK.

A TYPICAL NETWORK HAS THE FOLLOWING THREE COMPONENTS:

SERVER: THE MAIN COMPUTER ON A NETWORK THAT PROVIDES SERVICES TO OTHER COMPUTERS ON THE NETWORK. A SERVER DECIDES WHICH COMPUTERS ARE TO BE ALLOWED TO ACCESS THE HARDWARE AND SOFTWARE ON THE NETWORK.

WORKSTATION: A COMPUTER CONNECTED TO A NETWORK. YOU USE A WORKSTATION TO ACCESS THE HARDWARE AND SOFTWARE ON A NETWORK.

COMMUNICATION CHANNEL: A PATH OR LINK THAT CONNECTS COMPUTERS OR PERIPHERAL DEVICES, SUCH AS PRINTERS AND DISK DRIVES, TO TRANSFER INFORMATION. CABLES ARE COMMONLY USED AS COMMUNICATION CHANNELS IN A NETWORK, BUT NETWORKS CAN ALSO TRANSFER INFORMATION THROUGH WIRELESS CONNECTIONS.

           

           

DEPENDING UPON THE AREA COVERED, A NETWORK CAN BE CATEGORIZED:

          1. LAN:

A LAN CONNECTS DEVICES WITHIN A LIMITED AREA, SUCH AS A HOME OR A SMALL GROUP OF OFFICES. IT COMMONLY INCLUDES COMPUTERS AND SHARED RESOURCES SUCH AS PRINTERS AND SCANNERS.

            2. MAN:

A METROPOLITAN AREA NETWORK (MAN) IS SIMILAR TO A LOCAL AREA NETWORK (LAN) BUT SPANS AN ENTIRE CITY OR CAMPUS. MANS ARE FORMED BY CONNECTING MULTIPLE LANS. THUS, MANS ARE LARGER THAN LANS BUT SMALLER THAN WIDE AREA NETWORKS (WAN). EG: CABLE TV NETWORK. 

3. WAN:

                        A WAN IS A NETWORK THAT CONNECTS DEVICES IN GEOGRAPHICALLY SEPARATED AREAS. YOU CAN USE THE RESOURCES OF A WAN TO CONNECT TWO OR MORE LANS BY USING LONG WIRES, OPTICAL CABLES, AND SATELLITES. THE INTERNET IS AN EXAMPLE OF A WAN.

          

           

INTERNET

THE INTERNET IS A WORLDWIDE COLLECTION OF PUBLIC NETWORKS THAT ARE LINKED TO EACH OTHER FOR INFORMATION EXCHANGE. “NETWORKS OF NETWORK IS CALLED INTERNET.”

WWW:-

           

THE WORLD WIDE WEB (WWW), OR THE WEB, IS ANOTHER SERVICE THAT THE INTERNET PROVIDES. WWW INCLUDES SPECIALLY FORMATTED DOCUMENTS THAT ARE INTERLINKED AND STORED ON SERVERS AROUND THE WORLD.

INTRANET

MANY ORGANIZATIONS USE A SPECIAL TYPE OF NETWORK TO COMMUNICATE AND SHARE INFORMATION WITHIN THE ORGANIZATION. SUCH A NETWORK IS CALLED AN INTRANET. AN INTRANET IS SIMILAR TO THE WWW BUT IS ACCESSIBLE ONLY TO AUTHORIZED USERS OF THE ORGANIZATION. “A PRIVATE NETWORK OF AN ORGANIZATION OR COMPANY IS CALLED INTRANET.”

SESSION 2. 

PARTS OF A COMPUTER

A computer has various parts, and each part performs a specific function. The following table describes the parts of a computer.

Input Device:-

Input devices are used to provide information to a computer, such as typing a letter or giving instructions to a computer. Some examples of input devices are as follows:

• Mouse: A standard mouse has a left and a right button. You use the left button to select items and provide instructions by clicking an active area on the screen. You use the right button to display commonly used menu items on the screen.            • Keyboard: A set of keys that resembles a keyboard on a typewriter. You use the keyboard to type text such as letters or numbers into the computer.            • Microphone: A device that you can use to talk to people in different parts of the world. You can record sound into a computer by using a microphone. You can also record your speech and let the computer convert it into text.
• Scanner: A device that is similar to a photocopy machine. You can use this device to transfer an exact copy of a photograph or document into a computer. A scanner reads a page and translates it into a digital format that a computer can read. For example, you can scan photographs of your family using a scanner.           • Webcam: A device that is similar to a video camera. It allows you to capture and send live pictures to other users. For example, a webcam allows your friends and family to see you when you are communicating with them.
	·       Stylus: A pointing device, similar to a pen, used to make selections and enter information by tapping on a touch sensitive surface. For example, to enter information on a personal digital assistant (PDA), you use a stylus. A PDA is a lightweight, palmtop computer. • Trackball: A pointing device that is an alternative to a mouse. A trackball consists of a ball that is rotated to move the pointer on a computer screen. You can use a trackball when you have limited desk space.

Output Device:-

		You use output devices to get feedback from a computer after it performs a task. Some examples of output devices are as follows:
	• Monitor: A device that is similar to a television. It is used to display information in visual form, using text and graphics. • Printer: A device that you use to transfer text and images from a computer to a paper or to another medium, such as a transparency film. You can use a printer to create a paper copy of whatever you see on your monitor. • Speaker/Headphone: A device that allows you to hear sounds. Speakers may either be external or built into the computer.
Central Processing Unit (CPU) and Memory :-

The Central Processing Unit (CPU) is a device that interprets and runs the commands that you give to a computer. It is the control unit of a computer. The CPU is also referred to as the processor. Memory is where information is stored and retrieved by the CPU. There are three main types of memory. 1.     Primary Memory:- • Random access memory (RAM): It is the main memory and allows you to temporarily store commands and data. The CPU reads data and commands from RAM to perform specific tasks. RAM is volatile, which means it is available only while the computer is turned on. The contents of RAM must be copied to a storage device if you want to save the data in the RAM.

	• Read only memory (ROM): It is the memory that retains its contents even after the computer is turned off. ROM is nonvolatile, or permanent, memory that is commonly used to store commands, such as the commands that check whether everything is working properly. 2.     Flash memory/Secondary Memory: It is a nonvolatile memory that retains data even after a computer is turned off. Unlike in ROM, you can erase or modify stored information. 3.     Cache Memory: - cache memory also called CPU Memory. It is high speed static random access memory (SRAM). It is store program instruction and data that are used repeatedly in the operation of programs or information that the CPU is likely to need next.
Expansion Cards
An expansion card is a circuit board that can be attached to a motherboard to add features such as video display and audio capability to your computer.
Expansion cards are also called expansion boards. Some types of expansion cards are described in the following list. • Video card: It is connected to a computer monitor and is used to display information on the monitor. • Network interface card (NIC): It allows a computer to be connected to other computers so that information can be exchanged between them. • Sound card: It converts audio signals from a microphone, audio tape, or some other source to digital signals, which can be stored as a computer audio file.

Storage Device: - You use storage devices to store computer information.

Storage devices can be divided into two types, internal storage devices and external storage devices. Some common storage devices are as follows: • Hard disk: A magnetic disk that is usually the main storage device on most computers. It can be an external or an internal device. • Floppy disk: A portable storage device that allows you to store a small amount of data. A disadvantage of this disk is that it can be easily damaged by heat, dust, or magnetic fields.

• CD-ROM: A portable storage medium that allows you to store 400 times more data than on a floppy disk. It is less prone to damage than a floppy disk. • DVD-ROM: A portable storage medium that is similar to a CD-ROM; however, it can store larger amounts of data than a floppy disk or a CD-ROM. A DVD-ROM is commonly used to store movies and videos.

Ports & Connection:-

A port is a channel through which data is transferred between input/output devices and the processor.

Some types of ports are described in the following list. • Universal serial bus (USB) port: You use this to connect peripheral devices such as a mouse, a modem, a keyboard, or a printer to a computer. • FireWire: You use this to connect devices such as a digital camera. It is faster than a USB. • Network port: You use this to connect a computer to other computers to exchange information between the computers. • Parallel port and serial port: You use these ports to connect printers and other devices to a personal computer. However, the USB port is now preferred to connect peripheral devices because it is faster and easier to use. • Display adapter: You connect a monitor to a display adapter on your computer. The display adapter generates the video signal received from a computer, and sends it to a monitor through a cable. The display adapter may be on the motherboard, or on an expansion card. • Power: A motherboard and other components inside a computer use direct current (DC). A power supply takes alternating current (AC) from a wall outlet and converts it into DC power.