What is the purpose of a contour line on a map?

The purpose of a contour line on a map is to represent areas of equal elevation. Contour lines connect points that are at the same height above a given level, usually sea level, which allows for a visual understanding of the terrain's shape and slope. By examining these lines, one can determine the steepness of slopes, the presence of hills, valleys, and depressions, and how elevation changes over distances. This makes contour lines crucial for various applications, such as hiking, planning construction projects, and land use management. Understanding the layout and spacing of contour lines helps users make informed decisions about navigation and land development based on topography.