I studied functional programming and I took terms like "expression", "evaluation", and "value" for granted until it clicked that these terms have intuitive mean

I studied functional programming and I took terms like "expression", "evaluation", and "value" for granted until it clicked that these terms have intuitive meaning when interpreted in colloquial/human terms. - Expression as in someone expressing themselves, a tentative gesture. - Evaluation as in scrutinizing something to learn what it's really about. - Value as in "valuable". We don't know if an expression is valuable until we subject it to evaluation, or we get an interpreter to interpret it for us.