What do contour lines on a map indicate?

Contour lines on a map primarily indicate the elevation of the terrain. These lines connect points of equal elevation, allowing users to visualize the shape and steepness of the land. The spacing between contour lines demonstrates how steep or gentle the terrain is: closely spaced lines signify steep slopes, while lines that are farther apart indicate a more gradual incline. This characteristic makes contour lines essential for understanding topography, navigating in outdoor environments, and planning activities such as hiking, which involves varying elevations.

Other options refer to different features: latitude is denoted by horizontal lines (parallels), vegetation types are typically shown using colors or patterns rather than lines, and weather patterns are represented through various symbols and colors on weather maps, not through contour lines.