php - What exactly does || mean?

return (empty($neededRole) || strcasecmp($role, 'admin') == 0 || strcasecmp($role, $neededRole) == 0);

What exactly does the || mean in this statement? Can someone put this in english for me.

I promise I've googled this but I guess I don't know what to google for because I can't find anything.

thanks:)