If you still don't get what it's about, just take a few minutes to join and explore the different applications that are available. At the risk of appearing spammy, here are some invites to the free tier:

https://join.app.net/p/nybhfhmhms https://join.app.net/p/rgvngqrnhh https://join.app.net/p/chvcvtwbjf https://join.app.net/p/dgccmgvzyx