If you've wondered what the rainbow pentagon thing is on here, it's the Fediverse logo :fediverse:
It's a public domain design, you can use it for any purpose, there's a high quality copy at:
https://commons.wikimedia.org/wiki/File:Fediverse_logo_proposal.svg
Technically there can never be an official logo as there's no central authority on the Fediverse, but this is by far the most widely used symbol of this place.
It represents all the different kinds of servers that make up this shared network. (More info: https://fedi.tips/what-other-kinds-of-servers-are-on-the-fediverse/)