* Scalar quantities only have magnitude (size or amount).

* Vector quantities have both magnitude and direction.

Speed only tells you how fast something is moving. For example, a car traveling at 60 mph has a speed of 60 mph. It doesn't tell you where the car is going.

Velocity, on the other hand, is a vector quantity. It tells you both the speed and direction of motion. For example, a car traveling 60 mph to the north has a velocity of 60 mph north.

In summary:

* Speed: Magnitude only (e.g., 60 mph)

* Velocity: Magnitude and direction (e.g., 60 mph north)