Introduction to Computer System - Concepts

A computer is an electronic device that can be programmed to accept data (input), process it and generate result (output) . A computer along with additional hardware and software together is called a computer system.

A computer system primarily comprises a 

• Central processing unit (CPU)
• Memory
• Input / output devices 
• Storage devices. 

All these components function together as a single unit to deliver the desired output. 

Central Processing Unit (CPU)

The CPU is often referred to as the brain of the computer. CPU carries out the processing of data. It performs arithmetic and logic operations. 

The CPU is given instructions and data through programs. The CPU then fetches the program and data from the memory and performs arithmetic and logic operations as per the given instructions and stores the result back to memory.

The CPU has two main components:

• Arithmetic Logic Unit (ALU) - performs all the arithmetic and logic operations that need to be done as per the instruction in a program.
• Control Unit - controls sequential instruction execution, interprets instructions and guides data flow through the computer’s memory, ALU and input or output devices. 

While processing, the CPU stores the data as well as instructions in its local memory called registers. Registers are part of the CPU chip and they are limited in size and number.  

Input Devices

The devices through which control signals are sent to a computer are termed as input devices. 

These devices convert the input data into a digital form that is acceptable by the computer system.  

Some examples of input devices include: 

• Keyboard
• Mouse  
• Scanner 
• Touch screen

Output Devices

The device that receives data from a computer system for display, physical production, etc., is called an output device. 

It converts digital information into human understandable form . 

Some examples of output devices include: 

• Monitor 
• Projector 
• Headphone 
• Speaker 
• Printer