Tree Pruning and tree trimming are often referred to as the same thing, but there is a distinction. Tree Pruning is applied for overall tree health, while tree trimming is used to shape and manage the tree growth. Both tree trimming and tree pruning may use the same methods, but the reason they are being applied is what makes the difference.
For example, if a tree is identified to have a branch that is starting to grow towards a hazard on the property, you can trim the limb to shape it’s growth away from the hazard. On the other hand, if a tree has diseased or dead limbs, you would prune the limbs, which would then encourage tree health and growth. In both tree trimming and tree pruning you are usually removing a tree limb, the only real difference is the intention.