We use several commands in our day to day Linux activities and support. You can also use help or man page for a list of commands and the available options for quick reference. Most basic sand majorly uses are as below: cd: You can use this command to change your working directory. You can easily reach you your home directly by “CD /” from any working location. PWD: This command displays the full path of your current working directory. Very use full while reviewing different directories during troubleshooting or system analysis. ls: This command displays complete of files and directories in your current working directory. You can additional parameter -l for permission details and -a for hidden or config files. We have lots of option to use with ls commands to have the required output. Mkdir / rmdir: You can use “Mkdir” command to create a new directory and “rmdir”  This command to remove or delete the directory. Su: This is a special command to log in with a specific user or switches user from one to the other.