This book gives a comprehensive account of the current understanding of globular
clusters and globular cluster systems. We describe the observed properties of these
objects and discuss the theoretical ideas that are believed to account for their properties.
A key theme of the book is to link the study of globular cluster systems to other
areas of astrophysics, such as galaxy formation and evolution. The text is designed for
graduate students working in globular cluster research, and as a resource for research
astronomers active in this area. We also hope that the connections we emphasize
between globular cluster systems and other astrophysical systems will make the book
useful to researchers in related fields