This is part three of a multi-part tutorial series that teaches how to build real-world software applications with JavaScript, TypeScript, Node.js, and React — starting from zero knowledge, all the way to launching into production. Go to Part 1: Introduction to JavaScript to start at the beginning. Part 3: Node.js: JavaScript on the command line A new context As stated before, running JavaScript code, and therefore, building JavaScript applications, is possible in several different contexts.