Input Process Output

What is a Computer

A computer is an electronic device that can accept input data and instructions, process them and give an output. The computer can also store the data, Instruction and the output if required. For example, a user can give input data 1, 2 and an instruction ADD to the computer. The computer process the data and instruction and the result=3 is displayed in the screen. The data, instruction and the result maybe stored in the memory of the computing device. The input devices gives the input data/instruction, CPU (Central Processing Unit) process them, output devices shows the output abd the memory devices (RAM, Hard Disk, etc) is used to store them.
The essential components of a typical computer include the following:

Input Devices
Input devices are those devices that give input data and instruction to the computer. Some example of input devices include keyboard, mouse, joystick, mic webcams, scanner, etc.

Keyboard: Keyboard is the most common type of input devices using which a user can give data and instruction to the computer. There are 4 types of keyboards depending on the type of connections used. They are

AT Keyboard
AT (Advanced technology)
Consists of 5 pin connector
most found in Pentium 3rd and early Pentium 4 computers
Now a days this technology is almost outdated.

PS/2 Keyboard
PS (Personal System)
Consists of 6 pin connector
Found in New generation computers.

USB- Keyboard
USB (Universal Serial Bus)

Wireless Keyboard
Keyboard without wires
Consists of a wireless connected from USB

Mouse is another input device that is used to point and select objects in the 2 or 3 dimensions of our computer. Basically there are two types of mouse, the wheel mouse and the optical mouse. The wheel mouse is a mechanical mouse which works by the mechanical movement of a ball. The optical mouse works with the reflection of the light. Again depending on the type of connection there are 4 types of mouse.

Serial Mouse
Consists of 9 pin connector
Connected in COM (Communication or Serial port)
Now this technology is almost outdated

pS/2 Mouse
PS (Personal System)
Consists of 6 pin connector
Found in new generation computers

USB Mouse
USB (Universal Serial Bus)

Wireless Mouse
Mouse without wires
Consists of a wireless connected from USB

CPU

the Central Processing Unit (CPU) or simply a processor interprets the computer program instructions and process data. CPU has two components, the Arithmetic and Logic Unit (ALU) and the Control Unit (CU). The ALU is responsible for caring out all the arithmetic calculations like additions, subtraction, division, multiplication etc. and all the logical computations. The CU controls and monitors all the operations of a typical computer. Examples of CPU are Intel Pentium 1, 2, 3, 4, Intel Dual Core, Intel Celeron etc.

Output Devices
The output device displays the result of the processing of the input data and the processed instructions. Example of output devices are Printer, Monitor, Speaker, Headphones etc.

Memory
Memory is the most essential component of a computing System. It is used to hold the data and instruction during the processing by the CPU. Memory is also used to run any program. Basically there are two types of memory; Primary and Secondary.

Primary Memory: The primary memory is the main memory of a computer that is used to run a program and to hold all the data and instructions for a short period of time (Temporary). The primary memory is of volatile type, which means it loses all information if the computer loses power. Usually, primary memory is of lower capacity (MBs to few GBs) RAM (Random Access Memory) is an example of Primary Memory.

ROM and RAM
Read Only Memory (ROM ) : We can only read information from a ROM. We cannot write new information, edit/modify existing information and delete information from a ROM. Eg CD-ROM

Random Access Memory (RAM) : We can read, write edit/modify and delete any information from RAM.

Secondary Memory: The secondary memory is of PERMANENT type and it is used to store unforrmation for a period of time. Usually, secondary memory is of higher capacity (in Gigabytes) Example of secondary memory include Hard Disk Drives.

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