How is a map primarily defined?

A map is primarily defined as a graphic representation of Earth's surface features because it visually conveys information about different geographic elements such as mountains, rivers, cities, roads, and political boundaries. This graphic nature allows for quick interpretation and understanding of spatial relationships and the layout of an area.

While other options touch on aspects related to geographic representation, they do not capture the essence of what makes a map distinct. A detailed written description offers textual information but lacks the visual component that defines a map. A digital layout may represent a map's evolution into technology, but the core definition remains centered on its graphic representation. Similarly, a photographic image of terrain provides a real-world image rather than the abstracted and symbolic nature of a traditional map. Thus, the defining characteristic of a map is its graphical representation, which effectively communicates complex spatial information succinctly.