10 Major Hardware Components of a Computer System:
1.) System unit - main part of a microcomputer , somtimes it called the chassis.
2.) Motherboard/Mainboard/System Board - Main circuit board of a computer.
3.) CPU (central processing unit) - the processor is the main "brain" or "heart" of a computer system.
4.) Primary storage - is the computer's working storage space that holds data ,instructions for processing and process data (information) waiting to be sent to secondary stage.
          "Two Types of Memory"
a.) ROM (Read Only Memory) - is colatile meaning it holds data even when the                                     power is ON or OFF.
b.) RAM(Random Access Memory) - is colatile itmeans it holds data only when                                     the power is ON.
5.) Expansion Bus - a bus is a data pathway several hardware components inside or outside a computer.
6.) Adapters - printed circuit boards that enable the computer to use a peripheral device.
7.) Power Supply Unit - installed in the back corner of the PC case.
8.) Hard Disk Drive (HDD) - is amagnetic storage device thyat is installed inside the computer.
9.)Optical Drive - is a storage device that uses lasers to read data on the optical media.
10.) Digital Versatile Disc(DVD) - designed to optically access data stored on a DVD.
I hope I help you