Common examples of acceleration in real life are an object falling and a car speeding up to pass another car. All falling objects will accelerate under the force of gravity until they reach a terminal (maximum) velocity, while a car generates the force to speed up from pressing on the gas pedal to burn more fuel for energy.
Acceleration tells a person if an object's speed is increasing over a period of time. An object can accelerate while already moving, such as a car overtaking another, or from a complete rest, such as a car speeding up after stopping at a red light. The standard units for acceleration are meters or feet per second squared.