Heh, you must be new here.

Both are social networking sites. You can form small communities within a large community (FB groups/pages or Reddit subreddits) based on your interest. You can share just about anything most some of the same things on FB that you can here. News, pics, your fucking cat, what your shit looked like, whatever. You can try to buy stuff, sell stuff, give stuff away, whatever.

With both, you can see what you want. I don't want to see anymore of the aforementioned cat videos. Hide it away, filter it, keep scrolling. You can look at the cute cat, read the link or check out some comments. Don't like it? Hide it. It offends you? Report it. It interests you? Find other subreddits or a FB page for more fun.

Obviously, since Fb wants all the mines, infos, and users with the least amount of internet drama, they censor way too much stuff. Here, reddit doesn't give two shits about censoring is a lot more lenient and community controlled for the most part. I've watched report brigades happen on FB as often as downvote brigades here.

Here, you get thrown into a bunch of stuff at first so it's easier to find what you like. It's easier to make communities. It's hard to do that on FB. You have to hunt and search to find active communities. Shit, for the most part, you actually have to know people in real life to get friend requests (outside of gamers, celebrities, and attention whores). Here you don't, you're kind of friends with everyone at first. To me that's the coolest part and biggest difference between the two - instant community. It takes too much work to get find active online groups on FB.

Oh, there's something I didn't think about. FB is made for more active people, not a bunch internet- and gaming-addicted basement dwellers (not everyone here of course). If you remember, waaay back in the day it was so people can share tidbits of their life while they were busy in school. Here, reddit is kind of designed to keep you online, to reduce your need to interact with real live people. You don't have to leave your house to have "conversations with real people". (Conspiracy theorists, please do something with this. Take this and fucking run with it. Make it involve aliens and reptiles and share with everyone.)

While they may have different goals on what they want to become, the current incarnations of FB and reddit are very very similar.

That was a lot longer than what I thought I was gonna write, sorry. You get the idea. Both platforms are very similar and can be so much more, but it takes a village and all that shit. Welcome to reddit.