Also known as a folder in Windows, a directory can contain other directories or files. Directories are used to help in organising the files on your computer so that it is easily remembered for later access. The structure of a directory is like a tree and as you move up the tree you will finally reach the root directory of the drive. The root directory will contain many directories, usually grouped according to functions. Some directories are created by the system and any modifications to the directory or its contents should be handled with extreme care. Other directories are created by application software where files necessary to its smooth operation are stored.