What does a contour line show?

The steepness or the gentleness of the slopes is depicted by contour lines.

A contour line is a function of two number of variables which forms a curve connecting the points of the equal value. It is a three dimensional diagram with the function with x and y variable parallel the plane (x, y) .

In cartography, a form line joins purposes of equivalent rise (tallness) over a given level, for example, mean ocean level. A contour map is a guide represented with form lines, for instance, a topographic guide, which along these lines indicates valleys and slopes, and the steepness or tenderness of inclines.

The form interim of a shape guide is the distinction in height between progressive shape lines.