Differences between primary and secondary memory

	Primary storage devices	Secondary storage devices
1	These devices are temporary.	These devices are permanent.
2	These devices are expensive.	These devices are cheaper.
3	These devices are faster, therefore expensive.	These devices connect via cables and are slow, therefore cheaper.
4	These devices have less storage capacity.	These devices have high storage capacity.
5	These devices refer to RAM, ROM etc.	These devices refer to FDD, HDD etc.

(a) BIT (Binary digit): It is the smallest possible unit of information. It can be either 0 or 1.

(b) NIBBLE: Four bits form one nibble

(d) CHARACTER: It is represented by one byte. It can be a letter, digit, punctuation mark or special characters.

(e) WORD: The combination of 2 bytes or 4 bytes or 8 bytes is a word.

The data measurement

8 bits – 1 byte

1024 bytes – 1 kilobyte (KB)

1024 KB – 1 Mega Byte (MB)

1024 MB – 1 Giga Byte (GB)

1024 GB – 1 Tetra Byte (TB)

The teacher summarizes the lesson and allows student to ask questions to clear doubts.

Assessment :

1. Convert 144mb to byte

Assignment:

Make a research online about secondary storage devices and uses

See also

Types of Secondary Storage