Awesome! Now I get it! Thanks a bunch!

So it is not something that a normal user sees like a puzzle you need to solve before accessing a certain service?

So it is like a captcha?

Is this something I can deploy on my homeland for my web facing services? Or am I miss understanding the purpose

Do not buy a RPI for self hosting. Get a mini PC second hand. It is much much better. And to answer you question, yes you can host multiple services on a single server. Read about virtualization and start learning the ways of proxmox, also say goodbye to your loved ones :)))

I wonder if my pixel 7 pro that dies suddenly can do the same. I suspect the battery just packed up