Shared Users? What does that mean?

# Shared Users, huh? The Ring Doorbell Pro 2 has a feature called *Shared Users*. I'm sorry, I just don't get it. If I were to share my car with you, I've given you the keys to my car, you're out there driving it around. While you're driving it around, I certainly cannot be driving it at the same time. So, what is a "shared user"? I can't give you one of my family members that you then remove from my house. For me, the term *Shared User* conveys only confusion. What is the use case(s) that *Shared Users* is trying to address? Why would I care? What does it give me that not enabling it or using it, doesn't?