parent,+left-child,+right-child,+subtree,+root+and+leaf

The vocabulary of binary trees borrows terminology from both natural trees (those big things with leaves and branches etc.) and family trees (the organisation of parents, children etc.). In the sample tree below, the first node is the Root of the whole tree. Image taken from http://data-structures-demystified.org.ua/8157final/lib0050.html