Tree

A tree is a common hierarchical data structure used for many computer science applications. A tree is a recursive structure that usually maps an ordered set of data from an internal definition to some data space. Tree parts are often named after their contemporaries in family trees; trees contain nodes known as parent, child, and sibling.

Trees are made of nodes, which can contain both data to be stored and always link to further levels in the tree. Trees are often formed from a single node known as root; alternatively, trees may be built from a set of original nodes–this is known as a forest of trees.