A Red-Black tree is a type of self-balancing binary search tree that maintains its balance through specific properties. Each node in the tree is colored either red or black, and the tree follows rules that ensure no two red nodes are adjacent, and that every path from a node to its descendant leaves contains the same number of black nodes. This structure helps keep the tree balanced, allowing for efficient operations. The main operations on a Red-Black tree, such as insertion, deletion, and searching, can be performed in O(log n) time, where n is the number of nodes in the tree. This efficiency makes Red-Black trees a popular choice for implementing associative arrays and sets in various programming languages and libraries.