* Velocity is the rate of change of an object's position. It tells you how fast an object is moving and in what direction.

* Acceleration is the rate of change of an object's velocity. It tells you how quickly the object's velocity is changing.

Here's an example:

Imagine a ball thrown straight up into the air.

* At the very peak of its trajectory, the ball momentarily stops moving. Its velocity is zero.

* However, gravity is still acting on the ball, pulling it down. This means the ball's velocity is changing, even though it's momentarily at rest. Therefore, it has an acceleration (due to gravity) even though its velocity is zero.

In short: An object can be momentarily at rest (zero velocity) and still be accelerating. This often happens when an object is changing direction or experiencing a force that is trying to change its velocity.