     |
Where do funtions live?
- At runtime
During program execution functions live in the text segment of a program which is immutable. Each function has an address just like a data variable but in a different segment. The function name is only an alias for programmers. Internally functions are known only by their address.
- At compile time
When code is compiled (see below) the code statements are usually collected in archives (libraries). If a program needs a function, the proper library is "linked" to the program and it learns about the address of the function. The address is at runtime used to call the function.