Computer memory can be divided into primary and secondary storage. Primary storage includes RAM, which is volatile and temporarily stores active data. Secondary storage includes various disk-based and optical storage like hard disks, CDs, DVDs, and USB drives, which provide larger but slower storage that is not lost when the computer is turned off. Common examples of secondary storage media are hard disks, CDs, DVDs, and USB flash drives.

2. 4

3. • Chapter 1 Reviewing computers
• Chapter 2 Pioneers of Computers
• Chapter 3 About the CPU
• Chapter 4 Storing Data
• Chapter 5 Whiz through Software
• Chapter 6 Introducing Spreadsheet
• Chapter 7 Programming Languages
• Chapter 8 More on Multimedia
• Chapter 9 Computer Networks

4. Ch: 4

5. Contents

7. • Computer store data in its memory
• Computer main memory stores processed
data.

9. Computer have two kinds of memory
1. RAM(Random Access Memory)
2. ROM(Read Only Memory)

10. RAM(Random Access Memory)

11. 1. RAM is available for the operating system
and programs when computer is running.
2. Data in RAM is temporary.
3. When we turn off the system , the data is
deleted.

12. A type of volatile memory that
stores information temporarily so that
it’s available to the CPU.

13. WEB
KEYBOARD
CPU
RAM
MONITOR

14. 1. Rom contains instructions for booting up
the computer.
2. Data in ROM is permanent.
3. Data is not erased when the computer is
shutdown.

16. 1. Primary storage
2. Secondary storage

17. • It is the internal memory of computer
• It includes the main memory or RAM.
• It can be directly accessed by the CPU.

18. • Secondary storage is external memory
• Storage capacity is large

19. EXAMPLES

22. USB

24. • Disc is a round plate
on which data is
saved.
• There are two kinds of
discs.
a. Magnetic disc
b. Optical disc

25. • Data on magnetic disc can be recorded
and erased several times
• Hard disk is magnetic disc

26. • it can be internal or external
• Internal hard disk is fixed

27. • External hard disk is portable.

28. Floppy disks were used
as external storage
devices some years
ago. But not anymore.
The icon for save
command in Microsoft
word is a floppy disk

29. • It is secondary storage device
• CD(Compact discs) are used to store
digital data and audio files

30. • CD-ROM stands for compact disc read
only memory

31. • DVD can store more data than CD

32. • Blu-ray discs are optical discs that can store
high-definition video files

33. • USB flash drive is a portable storage device
• It is compact ,fast and store large amount of
data in a small space
• They are removable and rewriteable
• Also known as pen drive