Options in Sage 9 istallation

I have a newbie question regarding Sage 9 installation.
During the installation process there are options to choose from, and I’m not sure that I fully understand all of them.
I’d be glad if someone can explain the purpose of each option, or at least let me know if my choices make sense.

Specifically, please explain the purpose of:
“Local development URL of WP site”
Why the default is http://example.dev
and not something like http://localhost/example.com

So here are the options with my choices, when running:
composer create-project roots/sage mytheme dev-master

If you use full great Roots stack then name your sites after their domain so it’s descriptive.

This dev url will be used later for serving your site locally from your virtual server where your database and word press install lives and updates are listened through proxyUrl (i.e http://localhost:3000) and rendered in your browser while you are developing your theme with the help of webpack