Basically, "furries" are animal people like in Disney's Robin Hood and Zootopia, and the fans of those creatures. There's some sfw art at !furry if you want to see. Humans in media are boring. :P
Personally, I've seen it to be a very open, accepting and welcoming community. So I guess I romanticise being with a group of like minded people, which is something I've felt lacking in my life.
... Annoyingly, due to its history as an lgbt-friendly splinter group, it's who a lot of the bigots started targeting when it became socially unacceptable to be honophobic online. Grumble grumble.