Which feature is primarily used in cartography to represent points of equal elevation?

In cartography, contour lines are specifically designed to represent points of equal elevation on a topographic map. These lines connect locations that share the same height above mean sea level, helping to visually convey the shape and slope of the terrain. When contour lines are closely spaced, they indicate steep terrain, while lines that are farther apart suggest gentle slopes. This representation is crucial for understanding landforms and relief, making contour lines an essential feature in geographic information and cartography.

Isotherms, on the other hand, show points of equal temperature, and isolines are a broader category that includes any lines connecting points of equal value for a given phenomenon (like pressure or rainfall). The concept of a gradient refers to the degree of change in elevation or value over distance, but it does not represent specific elevation points itself. Therefore, contour lines are the most precise answer for representing equal elevation in cartography.