File systems consist of groups of directories and the files within the directories. File systems are commonly represented as an inverted tree. The root directory, symbolized by the slash (/) symbol, defines a file system and appears at the top of a file system tree diagram. Directories branch downward from the root directory in the tree diagram and contain files and/or subdirectories. Branching creates unique paths through the directory structure to every object in the file system.
Collections of files are stored in directories. These collections of files are often related to each other; storing them in a structure of directories keeps them organized.
A file is a collection of data that can be read from or written to. A file can be a program you create, text you write, data you acquire, or a device you use. Commands, printers, terminals, correspondence, and application programs are all stored in files. This allows users to access diverse elements of the system in a uniform way and gives the file system great flexibility.
This section discusses the following:
Chapter 4, Input and Output Redirection
Chapter 8, Backup Files and Storage Media
Chapter 9, File and System Security