A binary search tree (BST) is a data structure that organizes data in a hierarchical manner. Each node in a BST contains a value, and it has at most two children: a left child and a right child. The left child's value is always less than its parent's value, while the right child's value is greater. This property allows for efficient searching, insertion, and deletion of values. In a BST, searching for a value starts at the root node and proceeds down the tree. If the target value is less than the current node's value, the search moves to the left child; if greater, it moves to the right child. This process continues until the value is found or a leaf node is reached, making BSTs an effective way to manage sorted data.