Emphasizing computational techniques, this book provides an accessible and lucid introduction to combinatorial group theory. Rigorous proofs of all theorems and a light, informal style make Presentations of Groups a self-contained combinatorics class. Numerous and diverse exercises provide readers with a thorough overview of the subject. While catering to combinatorics beginners, this book also includes the frontiers of research, and explains software packages such as GAP, MAGMA, and QUOTPIC. This new edition has been revised throughout, including new exercises and an additional chapter on proving certain groups are infinite. Aimed at advanced undergraduates, this book will be a resource for graduate students and researchers.