Floating End Condition: The curve is left "floating". It does not reach first/last control point. It is possible to have one end "Floating" and the other "Open".
Open End Condition: The curve "interpolates" (that is, goes through (or in this case, goes to)) the first and/or last control point.
Periodic: The curve is cyclic. [Note, I do not display any periodic curves.] This implies that the curve does not have a beginning or an end. (However, when it is implemented, you must choose a beginning point.)