This document summarizes the main hardware components of a computer including input devices like a keyboard and mouse, output devices like printers and speakers, and storage units like RAM and ROM. It also defines units of digital storage like bytes, kilobytes, megabytes, and gigabytes. Additionally, it describes common types of computers like laptops and tablets as well as examples of system and application software.

2. : Refers to the physical
components of a computer

4. Keyboard – keystrokes into electrical signals
Mouse – Movements of a mouse are
displayed on the screen

5. Printer – take text and pictures to print
them on paper
Speakers – produce sounds

6. Light pen – a light sensitive detector at its tip
Scanner – creates a picture file

7.  Control Unit
 Arithmetic and Logic Unit
The brain of the computer

8. • capability to store huge amount of data
• Expressed in terms of bytes
 1024 bytes = 1 kilobyte (KB)
 1024 KB = 1 megabyte (MB)
 1024MB = 1 gigabyte (GB)
 1024 GB = 1 terabyte (TB)

9. • Primary
- processor for storing data temporarily
- Random Access Memory (RAM)
• Secondary
- information for longer period of time
- Read Only Memory (ROM)

10. • prevents sudden power fluctuations and
failures battery contained in it
• provide power backup for 15 minutes to
1 hour

11. • Laptop - LCD monitor
- Keyboard
- Touchpad / Trackball
• Tablet PC - thin notebook shapes with
touch screen
- smaller,lighter than laptops

12. • System software
- DOS , Windows7 , UNIX.
• Application software
- Microsoft Office
- Windows Media Player