Binary files can be executable files that instruct the system to accomplish a job. Commands, shell scripts, and other programs are stored in executable files. Directories contain information the system needs to access all types of files, but they do not contain the actual file data. As a result, directories occupy less space than a regular file and give the file-system structure flexibility and depth. Directories are created and controlled by a separate set of commands.
Special files define devices for the system or temporary files created by processes.
FIFO files are also called pipes. Pipes are created by one process to temporarily allow communication with another process. These files cease to exist when the first process finishes. Block and character files define devices. The name of each file must be unique within the directory where it is stored.