In computer science, an AVL tree is a self-balancing binary search tree, and the first such data structure to be invented[citation needed]. In an AVL tree the heights of the two child subtrees of any node differ by at most one, therefore it is also called
A red-black tree is a type of self-balancing binary search tree, a data structure used in computer science, typically used to implement associative arrays. The original structure was invented in 1972 by Rudolf Bayer who called them "symmetric binary B-tre