A binary tree is a data structure in which each node has at most two children, referred to as the left child and the right child. This structure allows for efficient data organization and retrieval, making it useful in various applications such as searching and sorting algorithms. Each node contains a value and pointers to its children, forming a hierarchical structure. In a binary tree, the top node is called the root, and nodes without children are known as leaves. There are different types of binary trees, including binary search trees, where the left child contains values less than the parent, and the right child contains values greater than the parent. This property enables quick lookups and insertions.