Units and file sizes

Bytes – File Sizes, Memory Sizes
Nibble		4 bits	(Only need to know this for the exam)
Byte	B	8 bits
Kilobyte	KB	1000 Bytes
Megabyte	MB	1000 Kilobytes	1,000,000 Bytes
Gigabyte	GB	1000 Megabytes	1,000,000,000 Bytes
Terabyte	TB	1000 Terabytes	1,000,000,000,000 Bytes

When we are talking about file sizes we usually use Bytes as our basic unit.

For a example:

We use the same metric system as in normal maths – kilo, mega, giga, etc with each being 1000 times large than the previous one.

If you converting from one unit of bytes to the next you just either times by 1000 or divide by 1000.

Example:

Bits – Network / Data Transfer Speeds
bit	b	1 bit
Kilobit	Kb	1000 Bits
Megabit	Mb	1000 Kilobits	1,000,000 bits
Gigabit	Gb	1000 Megabits	1,000,000,000 bits
Terabit	Tb	1000 Gigabits	1,000,000,000,000 bits

Usually expressed as a speed
E.g. 20Mb/s – 20 Megabits per second transfer speed