What Are The Parts Inside The System Unit And Their Function?


13 Answers

Sam Easterbrook Profile
Sam Easterbrook answered
The system unit is basically the whole computer minus the monitor and peripherals like keyboards, mice, speakers, webcams etc.
Most system units will be composed of:
  • Central Processing Unit
Usually referred to as the CPU, it's the brain of the computer and its most important part as it performs the instructions of computer programs and executes the functions of the computer.
  • Disk Drive
Most commonly a CD and/or DVD disk drive nowadays, though there are still computers in operation with floppy disk drives, they are used to read externally inserted disks so as to extract data off them.
  • Expansion Cards
These include graphics cards and sound cards that offer new functions and possibilities to the computer and its users. Most units will have spaces for these cards to be easily added.
  • Hard Disk Drive
Otherwise known as the hard drive, this is a computer's main  storage component, this is often confused with memory, or RAM.

  • Random Access Memory:
Commonly known as RAM, it supplies and holds information that the CPU uses while the computer is switched on, but does not store it to permanent memory.
  • Power Supply Unit
Like a battery, no juice no work! The PSU in most PCs converts the AC electricity from the mains into DC to eliminate surges that may damage the delicate infrastructure of the system unit.
  • Video Card:
Otherwise known as a display adapter, they are used as a medium between the system unit and the monitor.
Anonymous Profile
Anonymous answered
(Central Processing Unit)
(Random Access Memory)
(Read Only Memory)


Circuit board
Power Source/ Power Supply

Expansion Slots

Expansion Cards



Anonymous Profile
Anonymous answered
Parts of a system unit?
Anonymous Profile
Anonymous answered
azure trev Profile
azure trev answered
ALU and the CU ,, i.e arithmetic logic unit and control unit..these are the software parts

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