The scattering of high-energy electrons from nuclear and nucleon targets essentially provides a microscope for examining the structure of these tiny objects. The best evidence we have on what nuclei and nucleons actually look like comes from electron scattering. This book examines the motivation for electron scattering and develops the theoretical analysis of the process. It discusses our current theoretical understanding of the underlying structure of these systems at appropriate levels of resolution and sophistication, as well as summarising present experimental capabilities. Suitable for advanced undergraduates, graduates and researchers.