Payouts? Shard chats? What does it all mean?

So I keep seeing a couple of words floating around that I simply don’t understand, mostly “payouts” and “shard chats.” I understand the shard in shard chat is probably referring to arena shard, but what chat? And what is a payout? I’m assuming it’s not just the rewards the game gives you, and that it’s some kind of outside form of rewards? But I have no idea, and would love somebody to tell me what this all means.

(Edit) Probably not the best place to post this, but would love answers anyway