What is the difference between http module and express module?

Question

Express is not a "module", it's a framework: it gives you an API, submodules, and methodology and conventions for quickly and easily tying together all the components necessary to put up a modern, functional web server with all the conveniences necessary for that (static asset hosting, templating, handling CSRF, CORS, cookie parsing, POST data handling, you name it, it probably lets you use it).

The http API that's baked into Node.js, on the other hand, is just the http module: it can set up connections and send and receive data, as long the connections use the hypertext transfer protocol (with the relevant HTTP verb) and that's... well that's it. That's all it does.

They are completely different things. As many articles that you can find by searching the web for the details on both will tell you.