What is fn?

It seems like you're asking about "fn," but it's a bit unclear what you're referring to. "Fn" could refer to several things, depending on the context:

1. Function Keys: On a keyboard, the "Fn" key (short for "Function") is used in combination with other keys to perform special operations such as adjusting the volume or screen brightness.

2. Function in Mathematics or Programming: In math or coding, "fn" is often an abbreviation for "function." Functions are used to describe a relationship between inputs and outputs or to execute a specific task in code.

3. Project Fn: This is an open-source container-native serverless platform that you can run anywhere—on any cloud or on-premises.

4. FN Herstal: This is a leading firearms manufacturer from Belgium. They produce a range of military, law enforcement, and civilian firearms.

5. Entertainment or Media: Sometimes "FN" might refer to a show, game, or fictional character depending on the context.

If you have a specific "fn" in mind, please provide more details for a more accurate response!