Displacement versus Distance
Distance is a scalar quantity that expresses only the length of an arbitrary path (a curve in general, here in yellow). Displacement is the vector that specifies the position of a point or a particle in reference to a previous position, all with respect to an origin. The blue vector goes from the previous point to the current position.
Snapshot 1: in the real world it is very difficult to suddenly change the direction of motion by a large amount
Snapshot 2: a simple curve, like a road
Snapshot 3: a path composed of several straight lines
Snapshot 4: a complicated path, similar to that of a bee or other insect
Snapshot 5: taking small displacement vectors, the curve is a better approximation to the path
Snapshot 6: if the starting point and the ending point are the same, the displacement is zero