The Fediverse is a group of different software platforms (websites) that talk to each other. It’s a union of self-governing websites. The most popular platform is Mastodon, but there are lots of different Mastodon servers that all talk to each other. Pretty much all of the different Fediverse servers are different varieties of social media.
Here are some of them:
There are others for book clubs, music servers, stuff like facebook, etc.
Since they’re all federated, they all talk to each other. This means that you can follow someone’s PeerTube account on Mastodon; you’ll see their new videos show up on your Mastodon feed.
A very important feature of the Fediverse is that it’s not owned by one company. Recently Elon Musk bought Twitter (2022), and has been having a ball playing around and changing things. This hasn’t been very good for the people who use Twitter, or Twitter’s employees. But he can’t buy the Fediverse; no one can. He could buy a server, or even a few. But the rest of the Fediverse would continue on as before.
Each Mastodon website, PeerTube website, Pixelfed, CalcKey, WriteFreely, GoToSocial, etc. is totally independent. Each one is run by a different person or group of people, with different rules and target audience. And they all talk together, sharing information, posts, and so on. This is why it can’t be bought by a company. There are companies on the Fediverse, running their own Mastodon instances.
Fine. Mastodon is similar to Twitter. But it’s not the same. Some things are different; some aren’t there at all. This is frequently by design. The way Twitter does things has been bad for some people, and the idea is to make Mastodon be better.
This isn’t as hard as it looks at first. While Twitter is one company, and one website, Mastodon is literally thousands of websites. But you only need to join one. You can follow people on other Mastodon (or other Fediverse) sites.
Think of email. You have an email address, and it’s hosted somewhere. Perhaps gmail, or yahoo, or outlook, or hotmail, or zoho, or your company. It doesn’t really matter where, because all the email platforms send email to each other. They are all federated, so they work together.
The biggest instance (server) is mastodon.social, which is run by the same person who created most of the Mastodon code, Eugen Rochko. While you might think that you want to join the biggest, you may feel more at home at a smaller server. There are other general purpose servers (mastodon.world, mstdn.social, mindly.social, universeodon.com, etc.) Some are for more specialized use (infosec.exchange, defcon.social, dice.camp, etc.) Others are for certain geographical regions (glasgow,social, pnw.zone, mastodon.nz, etc.) Some use different languages (italian, german, etc.) You can start on one server, then move to another if you decide you’d rather be there.
While many of these are for different purposes (dice.camp is for tabletop role playing games) they aren’t exclusively for that. While you can expect to see lots of talk about D&D, Traveller, GURPS, and other games on dice.camp, they also talk about lots of other stuff. But there will be more talk about role playing games than on other servers. If you play D&D, you might want to be there.