Impact drivers are usually smaller (using 1/4" hex drive) for driving in smaller screws. Impact wrenches are larger and deliver more power, and are usually 3/8" square drive and larger. Impact wrenches are usually for loosening and fastening large nuts and bolts.

XR Stands for eXtreme Runtime. ( may also be called extended runtime) If it's stamped on the batteries: this is our claim that these batteries last longer than our non-XR versions. They are the higher amp hour batteries and have a larger fuel tank. If it is stamped on the tool: this means that the tool is brushless.

To briefly repeat thoughts about the Impact driver: It can't loosen car lug nuts either, although I did use it to run a nut down on a 1/2 stud to hold a vice to a metal bench and it was stringer than I expected.