Displaying phone number and email address in opportunity

Can someone let me know how we can display the contacts phone number and email list in the opportunity layout?

It appears that if we edit the primary address in either Leads, Accounts, or Contacts, it edits it everywhere. I am also wondering how this setup. Is it a relationship or some kind of portal?

Is there a way to display a field from another module in the layout?

Yes, but you’d need to build custom code to grab the field data.