R-B tree, also known as red black tree, is a special binary search tree. Each node of the red black tree has a storage bit to represent the color of the node, which can be red or black. The characteristics of red black tree are as follows
Nodes are red or black.
The root node is black.
Each leaf node (NIL node, empty node) is black.
The two children of each red node are black. (all paths from each leaf to the root cannot have two consecutive red nodes)
All paths from any node to each leaf contain the same number of black nodes.