Web programmers have to live on the command line. It gives us fast, reliable, and automatable control over computers. Web servers usually don't have graphical interfaces, so we need to interact with them through command line and programmatic interfaces. Once you become comfortable using the command line, staying on the keyboard will also help you keep an uninterrupted flow of work going without the disruption of shifting to the mouse.
For any command we discuss here, the command man, short for manual, will give a (hopefully) detailed explanation of that command. Sometimes that explanation will be too detailed for you. When you get lost and you want to understand, start again from the beginning of of the man page and repeat.
The command line is my home. I literally think of using the command line as walking around a building.
/ is the entrance - the root directory - but I usually start out in `/Users/rap
