| ls | Lists all files and directories in the present working directory |
| ls -R | Lists files in sub-directories as well |
| ls -a | Lists hidden files as well |
| ls -al | Lists files and directories with detailed information like permissions,size, owner, etc. |
| cd or cd ~ | Navigate to HOME directory |
| cd .. | Move one level up |
| cd directoryname | To change to a particular directory |
| cd / | Move to the root directory |
| cat > filename | Creates a new file |
| cat filename | Displays the file content |
| cat file1 file2 > file3 | Joins two files (file1, file2) and stores the output in a new file (file3) |
| mv file "new file path" | Moves the files to the new location |
| mv filename new_file_name | Renames the file to a new filename |
| sudo | Allows regular users to run programs with the security privileges of the superuser or root |
| rm filename | Deletes a file |
| man | Gives help information on a command |
| history | Gives a list of all past commands typed in the current terminal session |
| clear | Clears the terminal |
| mkdir directoryname | Creates a new directory in the present working directory or a at the specified path |
| rmdir | Deletes a directory |
| pr -x | Divides the file into x columns |
| pr -h | Assigns a header to the file |
| pr -n | Denotes the file with Line Numbers |
| hostnamectl | Get system information including, operating system, kernel, and release version |
| free -m | Display free and used memory in the system |
| tail filename | Display the last 10 lines of a file |
| head filename | Display the first 10 lines of a file |