Is there a list of the keys that can be used here. Is there a name for
these key / value pairs.
The “list” is in the Codex on the WP_Query page or you can just check the source.
I don’t know what kind of “name” you are looking for. Other that “key/value” I’d call them “arguments” or “parameters” (as does the Codex). I really don’t understand that part of the question.