(Electronic map). This term is used to describe a feature on some DVRs. It allows the user to import an image (like a layout drawing of a building) and place camera icons within the image to represent installed camera locations. Some allow you to click on an icon to see the actual camera video, initiate and cancel alarms, etc.
An E-Map (Electronic Map) is a digital layout used in surveillance systems to visually monitor camera locations and trigger alarms by clicking on camera icons.