Demonstrated interest:
some universities track link clicking, visits, others don’t. You can find lists on the internet, but also look on the page of the college.
All track a meaningful “interest” such as a request to interview, how early you added their school on Common App, how informed you are about their academic courses, campus organizations, and activities in your “Why type of essay”. Those why essays tell how much you time you spent researching on their webpage, how much attention you paid when you listened to their presentations, which all tell how interested you actually are.