Prefix

A prefix is the initial portion of some linear object (usually text or speech, but one could speak of the prefix of a parade) with a separate meaning, typically modifiying the meaning of the remaining part.

For example, the word prefix is made up of the base fix (meaning "attach" in this case), and the prefix pre-, meaning "before". To prefix is to attach before.

Specific types of prefixes include:

Prefix (linguistics), a type of affix that precedes the morphemes
SI prefix, used for magnitudes of SI units, like 'kilo' and 'milli' in 'kilometre' and 'milligram'.
Polish notation, a method of mathematical expression, also known as prefix notation
Telephone prefix, the first set of digits in a telephone number not a country code or area code
ITU prefix, a call sign for radio and television stations
Prefix (computer science), of a string
Prefix code

See also