The data structure commonly used for organizing hierarchical data is the tree. Trees consist of nodes connected by edges, with a single root node at the top and various leaf nodes at the bottom. Each node may contain data and links to its child nodes, creating a parent-child relationship that mirrors real-world hierarchical relationships. This structure is efficient for operations such as searching, insertion, and deletion, making it valuable in various applications, including databases and file systems. The tree structure is particularly effective for representing structured information like organizational charts and website navigation.