A directory structure is a way of organizing files and folders on a computer or server. It resembles a tree, where the root directory is at the top, and branches represent subdirectories and files. This hierarchical arrangement helps users easily locate and manage their data. In a directory structure, each folder can contain files or other subfolders, allowing for a clear organization of information. Common examples of directory structures include the Windows file system and the Unix file system, each with its own conventions for naming and organizing directories.