You’ll probably want to skip ahead if you already know what Mastodon is. Mastodon is a Twitter-like microblogging service. Where it differs from Twitter is that it is a decentralized service, i.e. there is no central place where all toots (the equivalent of tweets) from every user in the Mastodon universe, also known as the Fediverse, live. Instead, your toots live with one instance of Mastodon, the instance that you signed up with.