Here's why:

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

* Speed is how fast an object is moving.

* An object at rest is not moving, so its speed is zero.

* Since its speed is zero, and velocity includes direction, the object's velocity is also zero.

Important Note: Even though an object is at rest, it can still have potential energy due to its position or state. However, this is not the same as velocity.