I do concur, that Discord isn't really "social media" It's more of a chat program, where you can use text or voice in it. I think it's much better than using TeamSpeak, since you don't have to "pay" money, although subscribing does unlock a few features, in order to have something set up for a clan/guild to use, and the text chat area is a lot friendlier.
One of the nice things about it is with the voice part of it, you can be in the voice channel in Discord, while playing a game, and not have to use the voice part of any game. It can be rather annoying ingame, to listen to people screaming into their mics, or speaking languages you don't understand.