Full Hybrid
Full hybrids (or strong hybrid) are defined as hybrid cars that can run on just the batteries (electric part of the engine), just the gas (t...

Full hybrids are akin to having an electric car, but one that can run on gas, too. So, there's no need to plug it in, and you can (if needed) have the power and range of a gas engine.
The Toyota Prius and the Ford Escape Hybrid (SUV) are examples of hybrid cars with full hybrid engines. Both engines use Toyota's Hybrid Synergy Drive.
What this means in the real world. As with all hybrid cars, you still have regenerative braking and the gas engine will turn off when you come to a stop. But with a full hybrid, you can get away with driving on the battery alone at low speeds.
General Motors, BMW, and DaimlerChrysler are working together on a so-called Two-Mode Hybrid system. The Chevy Tahoe hybrid (2008?) will have this system installed.
Read more about the hybrid engine.