Mastodon is a reformulation of Twitter so that it can be controlled by the community, not a single corporation. Instead of a single site you go to, it is a “Federation” of different sites. When you post in one, that post gets transported to any other sites that has someone who follows you. If you just want to browse around, by default and without following anyone, you’ll see the posts on the site that is your home. Thus, it can be useful to find a home site that matches your interests.
I have an interest in Free/Open Source software, so I’ve got my
teeks99 account on the
fosstodon.org server. If you
want to follow/mention/etc me, you can use the address
@email@example.com, but if you just want to see my
account, you can browse to https://fosstodon.org/@teeks99.
FLOSSing for lent 40/40