An AVL tree is a type of self-balancing binary search tree. It maintains its balance by ensuring that the heights of the two child subtrees of any node differ by no more than one. This property helps keep operations like insertion, deletion, and lookup efficient, typically in O(log n) time. The name AVL comes from the initials of its inventors, Georgy Adelson-Velsky and Evgenii Landis, who introduced this data structure in 1962. By automatically adjusting the tree structure during insertions and deletions, AVL trees provide a reliable way to manage sorted data dynamically.