Working with the Process Module and Environment Variables

A program that the operating system is currently running is called a process. Every time you type node app.js, the operating system starts a new process, gives it an identifying number, and passes it the words you typed and a set of named settings. When your code has finished, the process ends and reports a number that tells the terminal whether it succeeded.

Node.js gives your code access to all of this through one object named process. This lesson uses it to turn the to-do list from the previous lesson into a command-line tool, `todo.js