An index lists key concepts, names and terms mentioned in a book and gives the page numbers where information about the topics appear. "A good index reduces the frustration of information overload, saves time and reveals relationships among concepts in a book," explains Martha Osgood of Back Words Indexing.
Typically, information in an index is arranged in alphabetical order. This allows readers to quickly determine if the book has the information they seek. An example of an index entry is "Tax returns, preparing and filing, 210, 417-18." This entry tells you on page 210 and from pages 417 through 418 you will find information regarding general tax returns, preparing tax returns and filing tax returns.
An index offers alternate terms or names under which a subject may appear. For instance, under the entry "autos," you may find the instruction, "Also see vehicles." In addition, an index offers subentries to elaborate upon topics that contain a range of different information. For example, a subentry under "life insurance" may include "annuities, 155-156" or "buying insurance, 145."
A glossary is an alphabetical list of terms on a certain topic or subject. Typically, a glossary includes terms that are uncommon or specialized within a subject. It provides a definition of a particular term and explains what a term means in context, much like a general dictionary. Glossaries may appear in the back of a book, or they may be attached to the ends of chapters or sections.
Rather than searching through a chapter, section or the entire book for a definition, a glossary provides quick access to basic information. It also serves as a study tool for students. Looking at the glossary before reading a section or chapters can help the student get familiar with the particular subject or topic.
An index is located in the back of a book or publication. However, a glossary may appear in various locations. Most glossaries appear in the back of the book near the index. However, some textbooks have glossaries at the end of sections or chapters. They may also have an inclusive glossary in the back of the book.