- The Bolder/Thick/Wider Brown line: has the elevation marked in the pic above it is 700 ft and another one at 800 ft. it is called Index Contour.
- The Thin Brown line: represent a line of equal elevation. in the picture above each brown thin line is equally 20ft in elevation. it is called Intermediate Contour.
- Contour Interval: is the distance between each contour line. The contour interval is found at the bottom, center of the map or you can caculate it base don the map above Thick Brown to Another Thick Brown is 700 ft to 800ft and betwen them, there are 5 lines so each line must be 20ft but Contour interval is found at the bottom, center of the map, always.
