In the measurement units system, the prefix "kilo" is to multiply by 1,000, "mega" to multiply by 1,000,000 end "giga" to multiply by 1,000,000,000.

These are powers of 10:

- 1,000 is 10 to the power 3,
- 1,000,000 is 10 to the power 6
- and 1,000,000,000 is 10 to the power 9.

Also, 1,000,000 = 1,000 x 1,000 and 1,000,000,000 = 1,000 x 1,000,000, so that a mega is 1,000 kilo and a giga is 1,000 mega.

But in usual computer science, it is not so: a kilobyte is 1,024 bytes rather than 1,000...