Binary Tree

Node's are called structures with a maximum of 2 children.
Since the number of children will be maximum 2, their names are identified as left and right.
Like left child and right child.
The maximum number of nodes at a given level is 2 ^ (l-1), l = level number.
For example, the maximum number of nodes in the third level 2 ^ 3 = 8.
height = the total number of paths from the desired node to the leaf below.
root height = 3 = height tree.
leaves height = 0

Some important tree types

Full Binary Tree: Each node has 0 or 2 children.
Complete Binary: Either all their levels will be full, or at least their nodes will be on the left as much as possible.
Perfect Binary Tree: All nodes will have 2 children plus all leaves will be in the same level.
A degenerate (or pathological) tree: If each node has 1 child. As you may have noticed, it looks very similar to the linked list.

It requires that all values that can be reached on each node from its left arm are smaller than the value of the node and that all values that can be reached from the right arm must be greater than the value of that node. And of course it also has to be a binary tree.
Because of ordering in BST, search is done fast.
In the worst case, the time complexity of searching and inserting operations is O(h). (h=height).