What do contour lines represent on a map?

Contour lines on a map are used to represent changes in elevation on the land's surface. They connect points of equal elevation, indicating how high or low the land is relative to sea level. By analyzing the spacing and shape of these lines, one can determine the steepness of slopes and the overall topography of the area. When contour lines are close together, this indicates a steep slope, while widely spaced lines suggest a gentler slope. Understanding contour lines is crucial for navigation and for assessing terrain features, which directly aids in planning movement through varied landscapes.