trees when we see tree in our everyday lives the roots are generally in the ground and the leaves are up in the air the branches of tree spread out from the roots in more or less organized fashion the word tree is used in computer science when talking about way data may be organized trees have some similarities to the linked list organization found in chap in tree there are nodes which have links to other nodes in linked list each node has one linkto the next node in the list in tree each node may have two or more links to other nodes tree is not sequential data structure it is organized like treeexcept the root is at the top of tree data structures and the leaves are at the bottom tree in computer science is usually drawn inverted when compared to the trees we see in nature there are many uses for trees in computer science sometimes they show the structure of bunch of function calls as we saw when examining the fibonacci function as depicted in fig figure depicts call tree of the fib function for computing fib( unlike real trees it has root (at the topand leaves at the bottom there are relationships between the nodes in this tree the fib( call has left sub-tree and right sub-tree the fib( node is child of the fib( node the fib( node is sibling to the fib( node to the right of it leaf node is node with no children the leaf nodes in fig represent calls to the fib function which matched the base cases of the function in this we'll explore trees and when it makes sense to build and or use tree in program not every program will need tree data structure neverthelesstrees are used in many types of programs knowledge of them is not only necessityproper use of them can greatly simplify some types of programs goals this introduces trees and some algorithms that use trees by the end of the you should be able to answer these questions how are trees constructedhow can we traverse tree(cspringer international publishing switzerland lee and hubbarddata structures and algorithms with pythonundergraduate topics in computer sciencedoi -- this copy belongs to 'acha