Programming paradigm
Many programming paradigms are as well known for the things they do not let people do as for those they do let people do. One time where this is true is functional languages. When a functional language is only or mostly functional, it usually will not allow side-effects. Another time where this is true is structured programming: it is different from normal imperative languages because it does not let programmers use "goto statements" (statements telling the program to go to an earlier step). Because of this and other reasons, people sometimes think new paradigms do not allow enough things. It is sometimes okay for the computer to not let people do things, though: it can help people avoid problems with their code, and let the computer make guesses that so it can run code faster, or even check code for problems before the code runs!