npm
npm does not stand for Node Package Manager. It is, however, the package manager for Node. (They don't say what it stands for.) It also has all the packages in the front end scene. npm makes a command line tool, called npm as well. npm allows you to bring in code from the npm registry which is a bunch of open source modules that people have written so you can use them in your project. Whenever you run npm install react (don't do this yet), it will install the latest version of React from the registry.
In order to start an npm project, run npm init at the root of your project. If you don't have Node.js installed, please go install that too. When you run npm init it'll ask you a bunch of questions. If you don't know the answer or don't care, just hit enter. You can always modify package.json later. This will allow us to get started installing and saving packages.