Mastodon isn't a single social media website like Twitter or Facebook - it's a network of social media websites. An instance of Mastodon can talk to another instance of Mastodon. So, a Mastodon user can follow another user and like or reply to their posts, whether they are on the same instance or a different one. A Mastodon instance can also see videos from PeerTube or images from PixelFed, and a Mastodon user can follow, like, and comment on all of these. Getting Started Finding An Instance

If you want your mastodon handle to be shorter or different from the domain that you are hosted on, you'll need to make use of a WebFinger.

How to know that your Mastodon instance needs upgrading

What type of hosting works best for you