Express is a popular Node.js web application framework that provides a set of features and tools for building web applications and APIs.It simplifies the process of writing web applications by providing a set of pre-built tools and conventions for common tasks, such as handling HTTP requests, serving static files, and rendering dynamic content.
In an Express application, you define a set of routes that map to specific URL patterns, and specify what action should be taken when a client makes a request to that URL. Each route can handle a specific HTTP method (e.g. GET, POST, PUT, DELETE) and can have middleware functions that are executed before or after the main route handler.
To install dependencies listed in the dependencies section of your package.json file, you can run the following command in your project directory: npm install