I wrote a small web server as a sample in this thread but ended up getting a bit carried away and adding a bunch of stuff to it. I decided to release it as a teaching tool since it gives a bit of insight into how web servers actually work. It shows how 404 errors, favicons, redirects and downloads work, among other things.
Please note that this is not the way you want to build a real website. If you want to build a real web site or web app it is best to do so with the technologies that were made for it like ASP.Net or Blazor. This project is for demonstration and learning purposes, not for building real websites.
You will need Visual Studio 2019 and .Net 5 to open and compile this project.
The following video demonstrates the web server in operation, executed on both Windows 10 and Ubunto 20.4:-