re: A question about typography, I think, unless the construction of the letters is called something else
Incidentally, you have intuited correctly that there is formally a distinction between typography (the selection, arrangement, and composition of type) and type design (creating the typefaces that will be used in typography). But your question is easily about either, because after it is created, the shape of a letter is still relevant to the person choosing to use it. Informally, "typography" is accepted as a catch-all for type related disciplines because it is a nice word and the job of typographer has been democratized practically out of existence anyway.
re: A question about typography, I think, unless the construction of the letters is called something else
@Felthry @Hayling
A horizontal stroke in the middle of a letter is "crossbar". The words we use for type anatomy are a lot messier than one would expect, and we often have to make things up when describing something, but this term will be understood by the most people.