zoom level

The geographic zoom level of an object or geographic entity is a number designed to interact with any of various mapping programs, indicating how much of the planetary surface should be shown on the map in order to offer an optimal view of the object or entity.

The value controls the amount of surrounding area visible with the subject. A broad area and a small object can require different viewing scales to be seen usefully.

Latitude and longitude locate a point. Zoom controls the view around that position without changing the point or the object's extent.