Speed is the rate a change of motion while velocity is the eate of change of speed in a particular direction.
speed is a scalar quantity while velocity is a vector quantity.
speed of a moving object cannot be zero while velocity of a object moving in a curved path is zero.
Speed is a scalar quantity which deals with only the rate of change of distance but not direction.
And Velocity is a vector quantity which deals with the rate of change of displacement(or the position of the object) as well as the direction.