Following people on the Fediverse
Glommer speaks ActivityPub, the standard behind Mastodon and the wider Fediverse, so you can follow people on other servers and read their posts here.
Open User Settings from your name in the top-right, find the Fediverse section, and paste in one or more handles - written like @user@example.social - then press Follow. Any separator between multiple handles works, so you can paste a whole list at once.
The same section lists the accounts you already follow, and whether each one has accepted yet or is still pending - some accounts out there approve their followers by hand rather than automatically. Mentioning a remote account by its full @user@server handle in a post works too - see hashtags and mentions.
Being followed from out there
You have a Fediverse address of your own: @your-username@this-site's-domain. Anyone on Mastodon, Threads, or another ActivityPub server can search that handle and follow you - no approval step, since everything here is public anyway.
Your posts travel to your followers as you publish them: text, pictures, video, polls, sensitive marks and content warnings, even your pinned posts and profile edits. Their likes, boosts, and replies land back here and count like anyone else's. Reposting a remote post tells your followers about it too.
If you ever leave for another server, Moving Servers in Settings sends your followers along - see the section there for the handshake it needs.