A tree structure is a way of organizing data that resembles a tree, with a single root node at the top and branches leading to various child nodes. Each node can have multiple children, but only one parent, creating a hierarchical relationship. This structure is commonly used in computer science for representing data such as file systems, organizational charts, and databases. In a tree, the top node is called the root, while the nodes without children are known as leaves. Tree structures allow for efficient searching, inserting, and deleting of data, making them useful in algorithms and data management systems.