The differential compensates for different wheel speeds of driven axles.
Different wheel speeds occur when cornering because one wheel of an axle travels a longer path than the other. In the process, the outside wheel rotates faster than the one on the inside of the bend.
Speed compensation of the driven axles in most cases is taken care of by a bevel gear differential. A limited-slip differential directs power to the wheel with the better traction and prevents the other wheel from spinning freely.