trees tree is hierarchical form of data structure when we dealt with listsqueuesand stacksitems followed each other but in treethere is parent-child relationship between items to visualize what trees look likeimagine tree growing up from the ground now remove that image from your mind trees are normally drawn downwardso you would be better off imagining the root structure of the tree growing downward at the top of every tree is the so-called root node this is the ancestor of all other nodes in the tree trees are used for number of thingssuch as parsing expressionsand searches certain document typessuch as xml and htmlcan also be represented in tree form we shall look at some of the uses of trees in this in this we will cover the following areasterms and definitions of trees binary trees and binary search trees tree traversal