What's the difference between a web server and a development server?

So a bit of context - I'm trying to give my create-react-app project a backend using express.

I'm following a tutorial that talks about having two servers working concurrently. This leaves me a bit confused - what's the difference between a web and a dev server, and how you can have two servers working simultaneously?

I think the underlying issue here is that I only have a shallow understanding of what a server actually is: I only understand it as being a process that listens to requests and sends responses.

Cheers

The tutorial most likely refers to the following definitions:

• development server

  • available at localhost
  • runs on your local machine (i.e. your PC, virtual box, etc.)
  • intended for local development and testing

• web server

  • available at an IP address or domain
  • runs on a remote server like a cloud server such as Google Cloud / Heroku / Digital Ocean
  • intended for production for your real users