Glossaries are especially helpful for understanding technical terms in academic texts. I used the glossary at the end of the biology book to understand the term 'photosynthesis'.
Pro Tip 2/3
Dictionary Difference
Unlike a dictionary, a glossary is usually subject-specific and not as comprehensive. The physics glossary explained terms like 'quantum', but didn't have common words like 'apple'.
Pro Tip 3/3
End-of-Book Feature
Look at the end of academic books for a glossary to clarify specialized vocabulary. Unfamiliar with the jargon, I turned to the glossary in the back of the textbook.