continuations? closures? things that are very similar to other things when expressed concretely, but actually exist at different levels of abstraction? things

continuations? closures? things that are very similar to other things when expressed concretely, but actually exist at different levels of abstraction? things that are counter-intuitively awkward to express by way of examples, because too many things are examples, sometimes in multiple subtly different ways? adjunctions (etc.) in category theory seem like 'above paragraph : the movie', but i can't claim to understand them in full generality so i'm unsure.