* Speed is a scalar quantity, meaning it only has magnitude (how fast something is moving).

* Velocity is a vector quantity, meaning it has both magnitude and direction.

* Acceleration is also a vector quantity because it describes the rate of change of velocity, which includes both speed and direction.

Example:

* A car traveling at 60 mph is describing its speed.

* A car traveling at 60 mph east is describing its velocity.

* A car accelerating from 0 to 60 mph east in 6 seconds is describing its acceleration.

Therefore, both velocity and acceleration include the direction of an object's motion.