Domains matter in email addresses. Domains matter in links. Domains matter because they name a thing. This allows us to create an expectation. This is also wh

Domains matter in email addresses. Domains matter in links. Domains matter because they name a thing. This allows us to create an expectation. This is also what certificates are based around. They certify that "The server you are talking to really has this name". This is important because names have meanings to people.