Snippets - what are they? How are they used?

Thank you. Yes, I'm aware of the commands and make use of them in worked with AI-generated files that I am editing. I am interested in getting into the more complex areas of commands and snippets.

So, please, anyone who might be using Snippets can you tell me what you do with them and how you use them. Actually, I tried to do an include to add the Snippets glossary to my base glossary and it crashed the program, so I guess that's not the way they are used.

I would love some examples.