A document outlining the conditions of use of a website and/or product purchased from a website.

Often, it lays out exactly how users can and can’t behave on your site or with your products, what you’ll do if visitors break those rules, and — conveniently — it’s where you wash your little legal hands of liability.

It’s also where you protect your intellectual property, trademarks, and all the other things lawyers like to get uppity about.