Semi-dwarfs can range in height from 10 to 16' and need annual pruning to keep the height down and the shape balanced. Very productive, this size tree will produce hundreds of fruit per season. Occassionally, trees will take a year off and produce little or no fruit, especially after a season of heavy production. Most fruit trees planted today are semi-dwarf, because they produce a large crop from a tree with manageable size for pruning and harvesting. That huge old apple tree in Grandpa's back yard is a standard, the only choice of size before the smaller hybrids were developed.
Standards require more space and are a bigger job to prune and harvest.
They take many years to reach full size, so it may be the grandkids who do the swinging. Ask at your local nursery for the varieties which do best in your area. Many exotic varieties are inviting, but the local varieties will produce best with the least effort. Match the tree to your soil. Plums, for example, do well in damp soil conditions which might not be good for apples.