Head
hg heads
A head is a ChangeSet with no children. The ["Tip"] is the most recently changed head. Other heads are recent ["Pull"]s into a Repository that have not yet been ["Merge"]d.
If you have just made a ["Commit"], that commit will be the ["Tip"]. Alternately, if you have just ["Pull"]ed from another ["Repository"], the tip of that repository becomes the current ["Tip"].
["Mercurial"] supports MultipleHeads concurrently within a single ["Repository"].