The Timber Mod for Minecraft 1.12 allows you to simply gain more wood, easier and faster than usual. By cutting the lowest log of a tree, using an axe, instead of gaining one block of wood, the entire tree will be cut down and the wood will fall to your feet. In turn, this mod helps both new and old players. This mod was simply created so that players can get started on their world as soon as they spawn. When the mod developer created this mod, I assume that his original idea came from previous experiences that he/she had when cutting wood. Maybe it got too boring, tiring perhaps. Whatever the reason, I know that many players share the same problem.
As much as this mod can improve gameplay significantly, when cutting both small and large trees, your FPS rate will drop dramatically. Make sure you know your computer can handle the mod before you use it, or simply use common sense. If you know your computer will lag or possibly already does, be smart when cutting down large structures or big trees.