From Bushwalk Australia
The term Summit, is most commonly used to refer the the highest point on a Mountain, Peak or Bluff. Often the mountain summit is marked on maps indicating the height at this highest point. At the location itself the summit may be marked with a variety of methods such as a Cairn, Trig Point Tower, or Trig Point Marker or no indication may be given at all.
Rather confusingly, a mountain for example, may have more than one peak, each of which has its own summit. Such an example is Cradle Mountain, which has four named peaks along it's ridge. The use of the word "summit" can be assumed to refer to the highest point of either a mountain or a peak depending on the context.