Contour line refers to an outline or silhouette of an object which is usually simplistic. In drawing and painting, a contour line is the edge of an object. When it comes to topographic maps, a contour line refers to a line which joins points of equal elevation. In other words, it is a line on a map that shows the shape and elevation of the land.

Contour lines are important in both drawing and painting, as they help to create the illusion of depth and volume. In topographic maps, contour lines are essential in helping to visualize the relief of the land.

There are a few things to keep in mind when reading contour lines on a map. The first is that contour lines always run perpendicular to the direction of the elevation. This means that if you are looking at a map from the side, the contour lines will appear to be curved. The second thing to remember is that contour lines never cross each other. If they did, it would indicate an error in the map.

Finally, remember that the closer together the contour lines are, the steeper the slope. Conversely, the further apart the contour lines are, the more gradual the slope.