Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion.
Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
Speed : the distance travelled by a body in a particular duration of time.I.E distance÷time
Velocity: displacement of a body in a particular duration of time...i.e displacement÷time.
As they are related because both have same dimensional formula and unit because both have similarity that we are using simliar formula , distance or displacement / time
LIKE IF SATISFIED.