Basically, it’s a normal, fuel efficient car that has two motors - an electric motor and a fuel powered motor. It also has a special system to capture braking energy to store in an onboard battery.
Specifically, electric motors use no energy during idle - they turn off - and use less than fuel motors at low speeds. Fuel motors do better at high speeds and can deliver more power for a given motor weight. That means during rush hour stop and go driving, the electric motor works great and, as an added benefit, does not produce any exhaust thus reducing pollution levels.
The fuel motors starts automatically when the battery gets low and proceeds to charge the battery. The engine doesn’t need any more maintenance than in any other car. Because hybrids have regenerative braking, brake pads may even last longer than those in normal cars.