There are many kinds of server types on the Fediverse (though Mastodon is by far the most popular right now).

For example, you can follow video livestreams such as @rstv which streams at https://live.retrostrange.com

Or you could follow a video account at @chriswere whose videos are hosted at https://share.tube/a/chriswere/videos

Although they appear to be Mastodon accounts when you interact with them within Mastodon, when you look at them on their home server they're clearly on a totally different platform.