Differences: Messages, Channels, DMs

Need to figure out (or just read & learn) what the differences are between Messages, Channels, and DMs.

Based on general understandings…
…not entirely certain what differentiates Messages from DMs. They both appear to be direct messages.
Messages can be sent to addressed to multiple people or a group(s).
DMs don’t appear to be functioning…? It seems like the DM is invoking the Channels “Chat” functionality.

So then what is Channels?
It seems to be a group chat function. But what would make that different than Category threads? Gonna guess that Channel Chats are live, real-time chats, whereas Category Threads are a typical post/reply/reply cycle. I’ll need someone else online in order to test Channel chats.

Yes channels are part of the Chat. Each chat room is a channel. Each Chat Channel will currently store chat data for 90 days.

You got the other part correct to.Post/Topics/Replies are perm. They say up unless deleted by a mod or admin.