What the devil is Tumblr?

It's a micro-blogging platform. So someone's tumblr page will be short posts or .gifs, pictures, videos, and stuff that tend to match a theme. Tumblr is kind of famously a more feminine end of the internet, but in a way that's kind of the raw, exposed id of the insanity of young women, as opposed to the insanity of young men. Famous for kind of fringe feminists, deranged fan sites, and hyper-focused weirdness. Not really my bag, but I get why its there.

Edit: And yeah, lots of porn. But that's everywhere online.