A "peephole" is a small opening, typically found in doors, that allows a person to see who is outside without opening the door. It is usually made of glass or plastic and is positioned at eye level. Peepholes enhance security by enabling homeowners to identify visitors before granting access. Peepholes can vary in design and may include features like wide-angle lenses for a broader view. They are commonly used in residential settings but can also be found in commercial buildings. Some modern variations include digital peepholes that provide video feeds to smartphones or screens inside the building.