Finishers are the player's main source of points. While punches and kicks deal damage, finishers are used to earn points in the thousands; because as Kreese says: "For the points, man. It's all about the points." However, do not that not all finishers earn the same amount of points, but some don't earn any.
Refered to by #13 as A Finishers, they are finishing moves that Jack can Preform by pressing the A button (What a shock) on a near-dead enemy. These finishers are preformed out of Jacks brute strength. Although they don't earn that many points, they can often be combined with Enviormental hazards (a Rose Bush, ideally.) for extra points.
There are two unarmed finishers involved here, but unlike other unarmed finishers, these are brutal as hell. Apart from those, the rest of these moves are done with the held weapon, or chainsaw. These are done by tapping B, and bloody up anybody attacked by them. There are many many more of these than "A finishers".
These very rarely kill an enemy on the spot, but they mostly garuntee that your target is no longer a threat. These vary from traps(Ramming an object on top of an enemy), to Impalings(doing just that with things such as Signposts). The first of these can only be done once to an enemy, but Impalings can be done a whopping 5 times to a single target.
These typically DO kill on the spot. Examples include Rose Bushes, fan blades, electrical hazards, burn barrels, and other spikes. These involve grappling an enemy, and throwing him into the hazards, or, for most spikes, you can alternately slam them on it at point blank multiple times. Four, to be exact.
Boss finishers are usually the most gruesome of all finishers. They may involve moving the Wii stick and nunchuck in certain ways, or not doing anything at all. Even though these usually kill bosses, you do not earn any points for them.