What is a hybrid vehicle and what are the main hybrid configurations?

A hybrid vehicle combines an internal combustion engine with an electric motor and battery for improved efficiency. Main configurations include: Parallel hybrid (both engine and motor can drive wheels), Series hybrid (engine only charges battery, motor drives wheels), and Series-parallel or Power-split (can operate in either mode). Mild hybrids have smaller motors assisting the engine, while full hybrids can drive on electric power alone for short distances.