A directory is a location for storing files on a computer. It’s a file system cataloging structure that contains references to other files or directories. Folders and files are organized into a hierarchical structure, meaning it’s organized in a way that resembles a tree. For example, a directory contained inside another directory is called a subdirectory. The terms parent and child are often used to refer to directories and subdirectories, respectively. The top-most directory in a file system is known as the root directory. Think of a directory as a filing cabinet that contains folders. Within these folders are files.
File systems use directories to organize files within a storage device such as a hard disk drive or solid state drive. System files may be located in one directory, while user files may be stored in another. Hierarchical file systems that include directories are Linux, MS-DOS, OS/2, and Unix. It’s worth noting that in a GUI such as Microsoft Windows, directories are known as folders.
By storing specific types of files in a folder, information can be easily accessed. Programs can be stored in a directory as well. When a program is installed, its files are stored in a directory that contains subdirectories with many files related to the program. Because of the directory, files are less likely to get overwritten, modified, or deleted by other programs.
To access a file within a directory, the names of all directories above it may need to be specified. To do this, a path will need to be specified. A path specifies a unique location by following the directory tree hierarchy expressed in a string of characters in which path components represent each directory. The delimiting character is most commonly a slash or a colon. With DOS and Windows the root directory is a backslash (). With Linux and Unix systems, the root directory is a forward slash (/).