What is the best way to express the margins of (i) the bounded side of a page and (ii) the edge side? I see people referring to them as left margin and right margin, but they are inaccurate. On even-numbered pages, what these people call left margin comes to the right and what they call right margin comes to the left. For the other two sides, I think top margin and bottom margin are okay.
In the most succinct terminology, the outer margins are the "margins" and the inner margins are the "gutter".