Usually fruit trees are grafted to root stock. the root stock is disease resistant and more vigorous than the trees' natural root system. Those are two reasons for grafting. You can tell if it was grafted by running you hand down the trunk to the ground. You should feel a knobbiness near the ground level if the tree was planted properly. If the branches are coming from below the knobby area then what is growing is a sport. It will not produce the type of fruit you get from the tree. Usually the root has very ppor tasting fruit and you don't want the tree to spend nutrients on the sports. Cut them off whenever they appear.
Next time you plant a fruit tree cut the leader-the center trunk off at your knee level. Don't cry over it. This will cause the tree to grow limbs just above that cut. the scaffold of the tree (the branches) will start lower on the trunk and therefore allow you to keep the mature tree at about seven feet in total height. that means it is not too tall to cover with bird netting to protect the fruit so the birds don't eat it. It will also allow you to spray it easily if the type of tree - peach, plum, nectarine, apple-requires it during dormancy. It also allows you to pick all the fruit without climbing a ladder and possibly falling and injuring yourself.
Honestly, I heard all about this and couldn't bear to do it to my first nectarine tree. It was a semi-dwarf. I thought I'd be ok with a semi-dwarf. No one told me a semi-dwarf matures to 25 feet in height and most of the limbs would be at my shoulder level or higher. I did it to my first cherry tree and I never need a ladder, the birds get none of my fruit, and my surrounding plants are not shaded by a huge tree. I swear by this method now.