If they are familiar with Reddit(Hackernews is closer but I doubt they use that) its like Reddit but with real money incentives and a community that values thoughtful discussion over thoughtless scrolling and liking.

If they are completely non-technical, don't use the Internet much then its a group of people that ask questions, share news, and debate topics in a forum with monetary incentives.

The best way to see how it works is to use it though.