Here's a breakdown:

* Velocity: Describes both the speed and direction of an object's motion.

* Acceleration: Measures how quickly the velocity of an object changes. It can be:

* Positive: Object is speeding up.

* Negative: Object is slowing down.

* Zero: Object is moving at a constant speed in a constant direction.

Formula:

Acceleration (a) = (Change in Velocity (Δv)) / (Change in Time (Δt))

Example:

* A car starts from rest (0 m/s) and reaches a speed of 20 m/s in 5 seconds.

* The change in velocity (Δv) is 20 m/s - 0 m/s = 20 m/s.

* The change in time (Δt) is 5 seconds.

* Therefore, the acceleration of the car is (20 m/s) / (5 s) = 4 m/s².

Let me know if you have any more questions about velocity, acceleration, or related concepts!