Main Parts of Computer :
(1) Central Processing Unit (CPU) : The Central Processing Unit is the brain of the computer. The Central Processing Unit is the unit where most calculations take place. It is linked with the input units and output units and output units to form the computer system. In terms of computing power, the CPU is the most important component of a computer system.
Central Processing unit is the combination of three parts :
(A) Memory
(B) Control Unit
(C) Arithmetic and Logic Unit (A.L.U.)
(A) There are two main types of memory :
(i) Main Memory —
RAM (Random Access Memory) : It is a volatile memory. It is the most common type of memory used in computer. It works with the CPU to hold instructions and data in order to be processed. But it can hold data only temporarily because it requires a continuous flow of electrical current. If current is interrupted, data is lost.
Cache Memory : A cache is a temporary storage area where frequently accessed data can be stored for rapid access. Once the data is stored in the cache, it can be used in the future by accessing the cache copy rather than recomputing the original data. The CPU and hard drive frequently use a cach
ROM (Read Only Memory) : It is a non-volatile memory. Data and instructions stored in it which can be read only not modified or destroyed. It is commonly used for storing program instructions that are not required to change. It is an internal storage area in the computer. It is a silicon chip on motherboard on which instructions are burned at the time of manufacture. When switched on, the computer instruction stored there is automatically initiated and after switching off instructions do not get los
(ii) Secondary or Auxiliary Memory : It is also known as auxiliary memory or backing store memory. Secondary storage does not lose the data when the device is powered down. It is non-volatile. Data that is not currently required by the CPU is kept on backing store and copied into main storage when needed. The most common storage media used as backing store is magnetic tape and magnetic Disc.
(B) Control Unit : It controls and directs the transfer of program instructions and data between various units.
(C) Arithmetic and Logic Unit : It performs all arithmetic operations and decision making operations. Performs arithmetic operations like (+, _ , ^ , * , /), logic operations like (AND, OR, NOT) and relational operations like (<, >, < =, > =).
(2) Input Devices : Information and data that is entered into a computer is called input. Devices that are used to give instructions to the computer are known as input devices.
(3) Output Devices : Output devices are those devices which display or give the results from the computer.
