Displacement
Displacement is the shortest straight-line distance from an object's initial position to its final position, along with the direction of that line. It is a vector quantity, unlike distance which is a scalar.
Example
If a student walks $4$ meters East and then $3$ meters North, the total distance is $7$ meters, but the displacement $s$ is calculated using the Pythagorean theorem: $s = \sqrt{4^2 + 3^2} = \sqrt{16 + 9} = \sqrt{25} = 5$ meters Northeast.