Answer: A hybrid electric vehicle and a plug-in hybrid electric vehicle both utilize their powerful electric motor and a gasoline engine to generate movement. They adapt on their own based on driving conditions, activating the electric motor and/or gasoline engine to propel the vehicle. Both vehicles also use regenerative braking, the most efficient way of putting energy back into the electric battery. This is the process of recovering energy that would otherwise be lost during deceleration so it can be reused to propel the car once acceleration is required.
The key differences between the two is that the plug-in hybrid has a larger electric motor and greater battery capacity allowing it to be used for a greater range of operation and distance. The plug-in hybrid plugs into an external electric source while the standard hybrid is solely fueled like a conventional gasoline vehicle.