One point on the board that a player can land a checker is an open point. It can be any place that doesn't have two or more checkers on it.
A point that isn't occupied by two or more opposing checkers.
A position on the board which one can occupy with a checker. Either there no checkers, or only an opponent's blot.
A point containing a single checker (blot), or no checkers at all. Either player may land on an open point.
Any empty point on the board not occupied by two or more men.