JavaScript is the language used to develop the Express.js framework, and it is also the language used to create the code that uses it .Express.js. This is one of the factors contributing to the popularity of the MEAN and MERN stacks, which include Angular/React at the front end, MongoDB at the back end, and Node.js and Express.js in the middle. A developer can easily create responses to particular URLs using Express' built-in route capability. These routes also accept parameters, expanding the app's functionality. Additionally, Express supports a variety of templating tools that let you create static HTML for a web browser. If you use this strategy, the server will produce the pages, so you won't need to.