A slip is different from a crab. In a slip, the aircraft is put into an attitude such that the relative wind is not aligned with the fuselage (through use of opposing aileron and rudder). This is commonly used for crosswind landings in small aircraft, as it allows the aircraft to point more directly down the runway (and in line with its ground track, but not with the relative wind) during the landing despite the crosswind. In a slip, there is a significant bank angle though, which could cause a large aircraft to drag a wing or an engine on the runway. In addition, a slip is somewhat disconcerting for passengers. Because of these reasons, large aircraft usually do crosswind landings with a crab rather than a slip.Can't speak much for this size aircraft, and it is impressive, but pilots start learning to do this very early in training. Doing this in a Cessna may well be the most fun you can have in a seated position. A crab is also called a forward slip. Another option is the side slip, where the fuselage stays aligned with the runway, but rolled towards the incoming wind. While just as safe, this is not done with unknowing passengers as being so tilted may make them too unneasy.