In this example, the working directory paths are set, the history is set to 20 lines, and it is given an alias of h (so the user can perform the history command simply by typing h). Similarly, 4gen is established as an alias for the command infogen-f. Finally, the path is defined as /usr/info/bin:/etc.
If this script file is included in the user’s configuration file, it will be automatically executed every time the user logs on. The exact name of the user configuration file varies from system to system, but two common names are .profile and .login. See the documentation for your system for specifics.