Here are some examples of that.
Displacement is a vector quantity which expresses that total change in position that results from a particular motion made by an object.
Displacement takes into account the direction in which a movement takes place. As you would imagine, the only two important points when determining an object's displacement are the start point and finish point.
Any other point covered during the object's motion is not important when determining displacement.
So, in order for an object to have zero displacement, its start point and finish point must be the same.
If an object starts its movement from point
A very good example is a runner that runs on a cicular track. If the runner starts and finishes the race at the same point, then its overall displacement will be zero.
This is true regardless of how many complete laps the runner manages to finishes.
Likewise, if you travel in a straight line from point
Another example would involve throwing an object straight up from ground level. On its way up, the object will travel for a distance of
On its way down, the object will again travel for a distance of
The object starts from ground level and ends up on ground level, so its displacement is zero.