Question about Ravelry

[cookworm]

Maybe I'm dense, but I'm not sure I understand what Ravelry's all about. Isn't it just a forum like here? It seems like some of the features I've heard people mention are just the same kinds of things you can post on a forum and get answers to, like questions about organizing yarn, what kind of yarns people used for their projects, etc. I feel kind of dumb because there seems to be a lot of excitement about it, but I'm not getting it. How does it differ from a forum like this one? Are there added benefits to being a part of it?