Uniform Acceleration -  If the change in velocity in equal intervals of time is always the same, then the object is said to be moving with uniform acceleration.

Example: a body falling from a height towards the surface of the earth.

Non-uniform or Variable Acceleration- If the change in velocity in equal intervals of time is not the same, then the object is said to be moving with variable acceleration.

Example - A ball thrown vertically upwards is moving with a negative acceleration as the velocity decreases with time.