Q. What is the difference between a thesaurus and a glossary?

For a good explanation of those two terms, which will allow you to identify differences between them, use the links below. The first links are from thefreedictionary.com. There are links for both glossary and for thesaurus.

The National Council on Measurement in Education has a really good definition of glossaries, with a link to a fuller explanation. Lastly, wiseGEEK has good definitions for both terms, which I've linked below.