An electric vehicle is a vehicle that uses a single or multiple electric or traction motors for propulsion. It may be powered by electricity derived from off-vehicle sources, or from a self-contained system of solar panels, battery or an electric generator. A hybrid electric vehicle (HEV) is a kind of hybrid vehicle, which integrates an electric propulsion system with an internal combustion engine. There are different types of HEV, of which the hybrid electric car is the most common form. Depending on the way in which power is delivered to the drivetrain, HEV can be classified into parallel hybrids, series hybrids and power-split hybrids. They can also be classified into mild and full hybrids depending on the degree of hybridization. Modern HEVs use innovative technologies such as regenerative brakes, motor-generators and start-stop systems, besides others. This book unfolds the innovative aspects of electric and hybrid vehicles. Most of the topics introduced in this book cover the principles, design and technology of HEV. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and trends in this field.