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, the root is always black, and every path from a node to its descendant leaves has the same number of black nodes. This structure helps keep the tree balanced, allowing for efficient operations. The main advantage of a Red-Black Tree is that it guarantees O(log n) time complexity for insertion, deletion, and search operations. This efficiency makes it a popular choice for implementing associative arrays and sets in various programming languages and libraries.