Express is the most popular Node web framework, and is the underlying library for a number of other popular Node web frameworks. It provides mechanisms to:

• Write handlers for requests with different HTTP verbs at different URL paths (routes).
• Integrate with "view" rendering engines in order to generate responses by inserting data into templates.
• Set common web application settings like the port to use for connecting, and the location of templates that are used for rendering the response.
• Add additional request processing "middleware" at any point within the request handling pipeline.

Source:

Express/Node Introduction - Learn Web Development | MDN. 13 Sept. 2022, developer.mozilla.org/en-US/docs/Learn/Serv...