you might know that it’s usually defined by some of its features, such as: reification of functions, avoidance or banning of functions with side-effects, use of

you might know that it’s usually defined by some of its features, such as: reification of functions, avoidance or banning of functions with side-effects, use of higher-order functions and so on The "function" in "functional programming" and the "function" in "avoidance or banning of functions with side-effects" are two different words, by the way! FP is named after the math word, not the programming language word, which means different things in different languages but usually means a kind of subroutine. FP means programming in a style that emphasizes composition of mathematical functions, and in an imperative language this generally amounts to writing your subroutines in a certain way. It just so happens that many imperative languages call subroutines "functions."