System Unit : 

Major components of system unit  

 Processor: 

 A computer engine, its brain. CPU (central processing unit) manages most of computer operations. Processors can be with pins or pin-less. It contains a control unit and a logic unit. 

RAM: 

A primary memory. It stores data processed by programs and apps on the computer. There are dynamic and static RAMs.

Motherboard: 

The system core. Actually, it is a heart of computer. Other system elements are connected to motherboard, and the whole system is managed and controlled by it. Motherboard contains special chips on which some ICs (Integrated circuits).  

Hard Drive: 

A system memory that stores data in a form of archives. Here all our files, folders, operating system, programs, and applications are saved. Hard driver can be of two type: PATA (Parallel Attachment Packet Interface) and SATA (Serial Attachment Packet Interface).

Video Card:

Outputs from a computer are displayed on the screen. Modern video cards support HDMI (high-definition multimedia interface), VGA (video graphics array) and DVI (digital visual interface). 

Power supply: 

 

Supply electrical power