I've seen quite a bit of "what even is this" on my federated timeline, so I'm gonna make this
What the hell is Mastodon?
Mastodon is a software for running self-hosted social networking services. It is, in essence, instant noodles but for SNSs. You get Mastodon, install it on a server, do some basic configuration, and you have a fully functional SNS.
So what's the deal with Mastodon?
The selling point for Mastodon is that it's federated. What this means is that a server (called "instance" in Mastodon) can talk with other servers that are compatible with it. So, for example, let's say you have the account @user1234 at the server coolsns.egg (Mastodon shows this as @[email protected]). For non-federated social media platforms, you can only interact with things on coolsns.egg. But in Mastodon, you can interact with things on other servers compatible with Mastodon. So in practice you can, for example, reply to a post ("toot" in Mastodon lings) by @[email protected] or follow @[email protected] Mastodon is compatible with everything that supports ActivityPub, which includes itself (obviously), Plemora, PeerTube (yes, there is a YouTube-like), and more.