This textbook highlights mechanisms, properties, observations, and research progress of solar and stellar rotation. The rotation of stars is a basic parameter that enters into the dynamo mechanisms that generates stellar activity. The faster stars rotate the higher stellar activity. Moreover, the rotation can also be used to determine stellar ages. Only in the case of the Sun we can directly observe details and therefore determine, e.g., the differential rotation. Thus, the Sun is a prototype for studying other stars. The textbook presents techniques that enable to determine rotation on stars and give a comparison of how stars rotate according to their spectral type and evolution. Special cases are given such as rapidly rotating stars that are strongly deformed into ellipsoids. The textbook is intended for professionals and students in Astrophysicists as well as readers interested in science in general.