| alias | Create a command alias. |
| awk | Search and replace text within a file. |
| cal | Display a monthly calendar. |
| chgrp | Change group ownership for a file or directory. |
| chmod | Change access permissions on a file or directory. |
| chown | Change ownership for a file or directory. |
| clear | Clear screen. |
| cp | Copy a file. |
| crontab | Schedule a task to be run at a later time. |
| du | Display a summary of estimated disk usage. |
| fdisk | Disk partition utility. |
| find | Search for files. |
| free | Display memory usage. |
| grep | Search a file for specific text. |
| gzip | Compression utility, handles .z files. |
| history | Display a list of recent commands. |
| kill | Kill a process. |
| ln | Create a link to a file. |
| locate | Find files. |
| ls | List files. |
| man | Manual application. |
| mkdir | Make a directory. |
| more | Displays the contents of a file by page. |
| mv | Move a file to a different directory. |
| passwd | Change password. |
| ps | Displays running processes. |
| pwd | Print Working Directory, displays current directory. |
| quota | Display disk quota information. |
| rm | Remove a file. |
| rmdir | Remove a directory. |
| rpm | Remote Package Manager, program installer. |
| set | Set shell variables and functions. |
| shutdown | Shuts down Linux system. |
| tar | Tape ARchiver, backup utility. |
| unalias | Remove an alias. |
| unset | Remove shell variables and functions. |
| useradd | Add a username. |
| w | List all users currently logged on, along with their current running process. |
| whereis | Searches for files within a hard-coded path (use 'find' to search exhaustively). |
| who | List all users currently logged on. |
| whoami | Display username. |