What's the difference between the deep web and dark web?and have you been on anyone of them?

It depends on who you ask really. The dark web as most know it is more of a decentralized web that works by preventing search engines from being able to search through the files and list them on the WWW. These "websites" are often self hosted places on the dark web and there are some places that keep a repository of active sites on them. Since web crawlers do not work on them and most use some form of encryption it is much harder to search/police than the WWW. So many things are offered there from college quiz answers to drugs and even darker things.

The Deep web are typically non indexed websites or file hosts that are hosted and accessible from the regular browser assuming you have the exact web address to connect to them.