Binary search trees allow searching, insertion, and deletion operations in O(h) time where h is the height of the tree. They represent dictionaries and priority queues. Keys in a binary search tree must satisfy the binary search tree property: all keys in the left subtree are less than the root key and all keys in the right subtree are greater. Red-black trees are a variation that ensures the tree remains balanced during operations to keep h proportional to the logarithm of the number of nodes.