Furriness is a weird mental disorder (dolphi will forgive :D) and fetish that makes people dig and/or identify as human-like furry animals, e.g. [cats](cat.md), foxes or completely made up species. To a big degree it's a sexual identity but these people just pretend they're animals everywhere, they have furry conventions, you see their weird furry talk in issue trackers on programming websites etc. You cannot NOT meet a furry on the [Internet](internet.md).
In the past we might have been wondering whether by 2020 we'd already have cured cancer, whether we'd have cities on Mars and flying cars. Well no, but you can sexually identify as a fox now.
Furries seem to have a very harmful obsession with [copyrighting](copyright.md) their art, many create their own "fursonas" or "species" and then prohibit others from using them. Stay away.