Emacs has all sorts of things bound to C-c C-c, depending on the mode. It's common enough that it's worth checking what it does in the current mode (With C-h C-k C-c C-c, of course).

First off, it would be "C-h k C-c C-c", not "C-h C-k C-c C-c" -- "C-h k" runs describe-key on the next shortcut typed.

Idiomatically, "C-c C-c" usually means something like "commit" - send an e-mail, compile source (by starting make), etc.

C-h m (the mnemonic is "help,mode") lists all the bindings for a give mode.

Also, pressing a prefix followed by C-h (i.e., "C-c C-h") defaults to listing all keybindings with that prefix. (Sometimes there are bindings replacing that, though, like "C-x C-h", which is delete-region.)

The funny thing is, I definitely would have typed "C-h k" in emacs. The hard part is trying to translate from muscle memory back into a string I can write down on HN.