Functional programs treat functions and data alike. No discrimination, if you will. That means, you can declare and use functions – assign to variables, pass to other functions etc., the same way you would play with variables.
A canonical example of a functional program would show how to pass functions as parameters to other functions (higher order functions). It would also show how one can create functions on the fly (lambdas or anonymous functions) and also assign it to a variable, which is of a predefined function type; either the compiler deduces or aligns to the calling context.