Web server from home without paralyzing internet at home

I'm looking for a way to run a simple web server that will be accessible from "outside web" from my home. I somewhat understand what I have to do, but my problem is that I can't give up my entire port 80 by port-forwarding, because I still need to use internet normally on the same network. Is there any solution that could help me?

Sorry if I'm not clear, I really don't know how to explain it.
Thanks in advance.