Why do you think it happens?
It has nothing really to do with SME, and there are lots of pages on services and ports.
You can run a http or https server on any port you want.
We accept by default http is on port 80 and https on port 443
Your web browser assumes this too (which can be bloody annoying).
So
http://10.97.1.1
is really
http://10.97.1.1:80Your browser adds the 80 itself.
Geneweb runs on a different port so it doesn't interfere with your normal web stuff. You could run multiple http servers all on different ports.
You can work the rest out yourself from the pages of FAQs written for you on the interwebs.