Express is a web development framework for Node.js. Node.js is an open source, cross-platform runtime environment for server-side and networking applications. It uses Google Chrome's JavaScript engine, V8, to execute code. Node.js is single-threaded and event-driven. It uses non-blocking I/O to squeeze every ounce of processing power out of the CPU. Express builds on top of Node.js, providing all of the tools necessary to develop robust web applications with node.
In addition, by utilizing Express, one gains access to a host of open source software to help solve common pain points in development. The framework is unopinionated, meaning it does not guide you one way or the other in terms of implementation or interface. Because it is unopinionated, the developer has more control and can use the framework to accomplish nearly any task; however, the power Express offers is easily abused. In this book, you will learn how to use the framework in the right way by exploring the following different styles of an application:
Setting up Express for a static site
Local user authentication
OAuth with passport
Profile pages
Testing