You probably are familiar with the microblogging platform Twitter, a big problem that it has, is centralization: this means that for you to use it you rely on their servers while being subject to any rules or code of conduct they decide.
To solve this, we have a thing called Activity Pub based platforms (I will refer to them as “fediverse” or “fedi” in short).
In this article I will be focusing on Mastodon which is the most popular platform; but feel free to research other platforms too!
Imagine you live alone, you have your own rules at home, you can visit your friends at their houses. Now imagine you live with 5 people, you probably need rules to live together, and ultimately if something bad happens, the house owner will have the last word on deciding to kick you out.
The former is the most similar to Twitter, and the first would be to host your Mastodon (or any fedi) instance, though a crowded instance could be similar to Twitter too!
An instance is a server hosting any fediverse platform, and you can access them via their URL (like any website) or via any fediverse app, this process of inter-communication is called federation.
Okay so, you sign up into a Mastodon instance, now lets say you have a friend that is into another instance, you can follow each other and interact!
How to choose a community instance
There are plenty of instances, they usually divide into interests or communities, but there are general purpose instances too.
Instances usually have their terms of service, code of conduct and can ban completely interaction with specific instances (the most common cases include racism, hate speech, etc.). Please be sure to read them before joining!
The official Mastodon website has a Find a server page that can help you!
Alternatively, you can visit this interactive wizard.
As much as I would love to recommend an instance, it is important that you, as a future guest, search for it and do your research about it.
Hosting an instance
There is also the option that you want be in total control of your data and self-host a fedi instance.
You, as an admin, can disable registration or make it invite-only if you want to induce your friends into it.
Keep in mind that, as any self-hosted service, maintaining a server can be a burden, and needs technical knowledge.
For self-hosting Mastodon, you can check its Github.
Tooting on the go
There is an official Mastodon app that you can download and login with your home instance.
Conclusion
I hope you can now comprehend what the fediverse is, and if you happen to join, please have fun!