This textbook covers all important aspects of mountain glaciers, from their formation and their importance as water reservoirs to the threat posed by current global warming. Glaciers themselves can also pose a threat to humans and represent a natural hazard in populated mountain areas in the form of ice avalanches and glacial lake outbursts. In addition, however, they are also important landscape formers and have helped to shape large parts of the present-day relief of the Earth, which is one of the classic fields of work of geomorphology and geology. In the individual chapters, the current state of research is presented in a comprehensible manner and illustrated with concise examples, photos and graphics. The book offers a compact introduction for all students of geosciences, curious mountaineers and laymen interested in nature.