SI prefix

A Si Prefix is a way of using a small number with a bigger meaning. It's like using abbreviations to express big numbers. For example, kilo- (k) stands for one thousand; so if someone said "2k" it would mean 2 thousand. The same is true for other Si Prefixes like mega- (M) for one million, giga- (G) for one billion, and tera- (T) for one trillion. This makes it easier to talk about very big numbers!