What do curved lines represent on a contour map?

On a contour map, curved lines illustrate points of equal elevation, also known as contour lines. These lines connect locations that share the same height above a specific reference point, usually sea level. By analyzing the spacing and shape of these curves, one can assess the steepness or flatness of the terrain. Closely spaced lines indicate a steep slope, while widely spaced lines suggest a gentle incline. This concept is fundamental in topography, geology, and geographical studies, as it allows for visualization of the landscape's elevation changes. The correct choice, therefore, emphasizes the critical role that contour lines play in representing terrain elevation.