yep, there is a right click key
useless considering there is no left click key
like why even bother adding this key, waste of plastic
It's called the Menu Key, and it's used for opening context menus.
It's intended use is for computers where right clicking isnt possible if a mouse doesn't have a right button, or if it's been disabled on public computers.
But really, it's an old button that doesn't have much use and was introduced back in 1994/95, making it as old as me, if not older. It would be fair to call it vestigial too, since a lot of keyboard manufacturers remove the key in order to put in more useful keys, like Fn.