A pathname indicates the location of a particular file or directory by outlining the route or "path" from the host name (if the file resides on a remote server) through the directory structure to the desired filename or directory name. Each name in the series of names that define a path are separated by a slash. If the file is located in the current working directory on your computer, it is referred to only by its filename.

Pathnames can be absolute or relative. An absolute pathname provides the full path (address) of a file, including the computer system, directories, and subdirectories (if any) it resides in. Relative pathnames are used to describe a file or directory location on the user's system relative to the user's current location on the system (i.e. based on which level of the directory structure the user is in).