Electric cars run at least partially on electricity. Unlike conventional vehicles that use a gasoline or diesel-powered engine, electric cars and trucks use an electric motor powered by electricity from batteries or a fuel cell.
Not all electric vehicles (or “EVs”) work the same way. "Plug-in hybrids" offer both a gasoline or diesel engine and an electric motor: the motor is powered by a battery that can be recharged by plugging in. Other EVs forgo liquid fuels entirely, operating exclusively on electricity ("battery electric" vehicles). Still others power an electric motor by converting hydrogen gas into electricity ("hydrogen fuel cell" vehicles).
Conventional hybrid vehicles also have an electric motor, but aren’t considered EVs as they can’t be plugged-in.
In terms of air pollution and greenhouse gas emissions, electric cars and trucks are often cleaner than even the most efficient conventional vehicles. Exactly how clean depends on the type of vehicle and the source of the electricity. When battery electric EVs are powered by the cleanest electricity grids, greenhouse gas emissions from EVs are comparable to a car getting over 100 miles per gallon. When charged exclusively with renewable electricity like solar or wind, charging and operating an EV can be nearly emission free.