Yeoman, Grunt, and Bower form a development stack where Yeoman is a scaffolding tool that generates boilerplates, Grunt is a JavaScript task runner for automating repetitive tasks like minification, and Bower is a package manager for fetching, installing, and managing third-party packages. The document provides instructions on installing each tool via Node.js and npm and using them together to build a web app, with Yeoman for generating the initial scaffolding, Grunt for automating build tasks, and Bower for managing third-party packages.