According to the article " Getting to Know Command Line ", the command line is the ultimate seat of power on your computer. It is simply a place where you type commands to the computer. Once we know the important commands, we can create files and run files and delete files so much faster than if we are using the mouse. How can we use the command line to interact with those directories and files? Firstly, we need to have a workspace. The course recommends us to use Goormide , which is an integrated development environment on the cloud. And it is developed by a Korean company. You can feel free to sign up and create your first cloud by following their introduction. Once you sign in the cloud, you can create your directory and files. The course introduces six useful Command to interact with directories and files. List/Change Directories Command LS LS stands for list, and it just shows us all the files and folders of the current folder. For example, in the te...