Here's why:

* Speed tells you how fast something is moving. It's a scalar quantity, meaning it only has magnitude. For example, a car traveling at 60 mph.

* Velocity tells you how fast something is moving and in what direction. It's a vector quantity, meaning it has both magnitude and direction. For example, a car traveling at 60 mph east.

In simpler terms:

Imagine two cars driving at the same speed. One car is driving east, and the other car is driving north. They have the same speed, but their velocities are different because they are moving in different directions.