A binary tree is another example of a data structure similar to a linked list, but instead of each node pointing to the very next node linearly, each node points to the two nodes, hence making this an example of a non-linear data structure. The tree structure is a way of representing the hierarchical nature of a structure in a graphical form. In the Abstract data type of trees, the order of the elements is not essential. If we need ordering information, linear data structures like a linked list, stacks, queues, etc., can be used.