* Acceleration has both magnitude and direction: A rocket's acceleration tells us how quickly its velocity changes *and* in what direction.

* Magnitude: How much the rocket speeds up or slows down (measured in meters per second squared, m/s²).

* Direction: The direction the rocket is accelerating, which could be upwards, sideways, or even downwards if it's slowing down.

* Vectors require both magnitude and direction: Scalars only have magnitude. Examples of scalars include speed, mass, and temperature.

Therefore, since the acceleration of a rocket has both magnitude and direction, it's a vector quantity.