Starting Point machine "Three" help to understand

Hi! i am new player here. I would like to seek help to better understand about this practice. I got the flag from a walkthrough but i am unable to understand some rational of this practise.

During the practise:
T1) I used the target IP to give a domian name for the website.
Q1) In real life scenario is it possible? I can use a website ip adress and assign a domain name of my choice using linux?

T2) After uploading the reverse shell to their server. I setup netcat to listen a port. Then I type in a URL to activate the reverse shell.
Q2) Am i simiulating the victim on typing the URL to activate the reverse shell?

Yes, but these changes are only local to your machine. Many operating systems support the use of a “hosts” file. Most OS configurations will query this file before doing a query to your configured DNS server.

You’re forcing the victim machine to run a command that will connect to your reverse shell. You can accomplish this in different ways on this target.