Electric bicycles and scooters, collectively termed electric two-wheelers (E2Ws), are an important transportation tool for the estimated 50 million users around the world. This article presents a primer on E2Ws. This article introduces the E2W and its different types. It then describes the global E2W market with a focus on China, the largest market. Next, key characteristics of E2Ws are presented, including cost, energy use, emissions, and safety. Electric two-wheeler battery technology is examined with a focus on valve-regulated lead–acid batteries and lithium-ion batteries. In the final section, the performance of E2Ws is discussed using data from actual road tests. A list of useful references on this subject is provided in the appendix.