Can displacement be zero(0)

Displacement can be zero even when distance is not zero. Consider two points A and B such that AB = 5 m. When a car travels from A to B and then back from B to A, distance = 5+5 = 10 m. Displacement = Minimum distance between final(B) and initial position(B) = 0. 

Displacement of a body is the change in its position.It is the shortest distance between the initial and final position of the body. So when the initial and final position of the body is same the displacement would be zero.

eg: If you are travelling along a circular track of radius r ,starting from a point A and you reach back at the same point A in some time.The distance travelled will be equal to 2πr (equal to the circumference of the track) . Since the initial and final position are the same the displacement = zero