OK, leaves and trim are NOT the same thing exactly.
Trim is the small leaves and such that are growing out of the actual buds that are not part of the bud itself. These generally have some trichomes on them but not enough to be worth smoking on their own. The trim can be saved to make things like hash or butter etc.
Leaves are just that, they are the leaves on the non-bud portion of the plant, aka fan leaves. These generally do not contain any of the things we are looking for to smoke, but many people do use them to make therapeutic extracts and such.