The document discusses the main hardware components of a computer system. It describes the system unit which houses the main components including the motherboard, CPU, RAM, expansion cards, and BIOS. The motherboard connects and allows communication between all the components via buses. Expansion slots on the motherboard can accommodate additional cards like graphics or sound cards. Storage devices, input devices, and output devices connect to the motherboard to allow interaction with the computer.

1. Computer Hardware
The physical part of a computer

2. Introduction
The physical parts of a computer are called
hardware. In this chapter, we will examine the
different types of hardware according to four groups:
The system unit,
Input devices,
Output devices,
Storage devices.

3. The System Unit
All of the main components of a computer

4. Chassis (Case)

5. Power Supply

6. Power Supply

7. Uninterruptible Power Supply (UPS)

8. Mainboard
The mainboard (also called the motherboard, or
system board) is the biggest board inside your
system unit. All the main components of your
computer connect to the mainboard. The CPU, BIOS
and chipset are normally situated on your
mainboard along with all the other electronic
components.
The storage devices, such as the hard disk and DVD
drive, are attached to the mainboard via data cables.
The expansion cards, such as the video card and
RAM modules, are attached to the mainboard via the
PCI and memory slots. The video and sound cards
can be integrated into the mainboard (onboard).

9. Mainboard

10. The ROM-BIOS (Read Only Memory-Basic Input
Output System)
This chip is a special ROM microchip on your
computer’s mainboard. It ensures that the BIOS will
always be available and will not be damaged by disk
failures. It also makes it possible for a computer to
boot itself.

11. The ROM-BIOS (Read Only Memory-Basic Input
Output System)

12. System Buses
Every component in the computer must be able to
communicate with the CPU through the motherboard.
This connection is done via a collection of copper or
gold tracings attached to the motherboard.
These tiny wires are called
buses. Buses carry data and
control messages between
the components.

13. The Bus Arbitration (Chipset)
The bus arbitration chipset is an integrated circuit on
the motherboard. It controls how the mainboard
buses are used. If two different devices try to use the
same bus at the same time, it can cause a problem.
The bus arbitrator prevents this problem.

14. Expansion Slots
Expansion slots hold expansion cards (such as a
video card, sound card, or network card) and
connect them to the buses.

15. ATA and ATAPI Interfaces
ATA & SATA
The current SATA standard provides significant benefits
over ATA in terms of convenience, power consumption, and
most importantly, performance.

16. Peripheral Connectors

17. Internal Speaker

18. Central Processing Unit (CPU)
A central processing unit (CPU) or processor is an
electronic circuit that can execute computer
programs. The CPU is one of the most important
components inside your computer. It is like the brain
of your computer, because it performs all the
computer calculations. CPU speed is measured in
gigahertz (GHz) and has an important effect on the
overall speed of your computer.

19. Central Processing Unit (CPU)

20. Memory (RAM)
RAM (Random Access Memory) is temporary
memory that the computer uses to store applications
and data that are in use, for example, the operating
system, and a word processor or database program.
RAM is called “random access” because any storage
location can be accessed directly. When you create
data such as a letter or a picture, the computer
stores the data in RAM and then copies them to the
hard disk when you save your work.

21. Memory (RAM)

22. Expansion Cards
An expansion card (also known as an add-on card,
internal card, or interface adapter) is an electronic
board added in a desktop computer to provide or
expand features not offered by the motherboard.
Expansion cards need device drivers to function
properly.

23. Some Types of Expansion Cards
Video cards
Sound cards
Network cards
TV tuner cards
Video processing cards
Modems

24. Graphic card