A contour line is a line on a map that connects points of equal elevation above a given reference point, usually sea level. These lines are precisely surveyed and provide accurate information abou

A contour line is a line on a map that connects points of equal elevation above a given reference point, usually sea level. These lines are precisely surveyed and provide accurate information about the terrain's height and shape.

A form line is a line on a map that indicates the approximate shape of the terrain, but not necessarily precise elevation. Form lines are used when exact surveying is not possible or practical, and they are less accurate than contour lines. They are often drawn freehand to give a general impression of the landform.

The key difference is that contour lines represent measured, accurate elevations, while form lines represent estimated, approximate shapes of the land.