M7 and M111 are the rootstock size/type and what determines if the tree is a dwarf/semi-dwarf/full grown. Remember apples are a LONG term investment. Semi-dwarves can produce in about 5 years, but it may take longer. Regular apple trees take much longer. The good thing is they last a long time. I try to plant a few new trees each year. Be open to other options as well though to cover your bases. Crabapples are good too. Pears, persimons, grapes, chestnuts, chinquapins, and plums are all good choices too. I have six mature hybrid chestnut trees and they produce several hundreds of pounds of 2" nuts each, every year. I am planting seedlings at other areas on the farm and the deer pour down the mountain for the two weeks the chestnuts are on the ground. But the trees drop all their nuts in about 3 days so the nuts are only available for about two weeks so other things are needed to have a sustained draw.