1. A contour line of a function of two variables is a curve along which the function has a constant value.
2. In cartography, a contour line joins points of equal elevation (height) above a certain fixed level. This fixed level is often sea level.
3. A contour map is a map illustrated with contour lines, for example a topographic map.
4. The contour interval of a contour map is the difference in elevation between successive contour lines.https://3f0bd79743d1e6296b35a4dd21a8cefc.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html5. An Isoline is a line on a map, chart, or graph connecting points of equal value.
Types of Contour Lines:
1. Isopleth – A line drawn on a map through all points having the same numerical value, as of a population figure or geographic measurement.
2. Isohyet – A line drawn on a map connecting points having the same amount of rainfall in a given period.
3. Isobar – A line drawn on a map connecting points having the same atmospheric pressure at a given time.
4. Isobath – A line drawn on a map connecting all points of equal depth below the surface of a body of water.
5. Isohaline – A line drawn on a map connecting all points of equal salinity in the ocean.
6. Isotherm – A line drawn on a map connecting points having the same temperature at a given time.
7. Isohel – A line drawn on a map connecting points having the same duration of sunshine.
8. Isohume – A line drawn on a map connecting points of equal relative humidity.
9. Isoneph – It is a line representing points of equal amounts of cloud cover.
10. Isopectic – A line drawn on a map connecting points at which ice begins to form at the same time of winter
11. Isotach – A line drawn on a map or chart connecting points of equal wind speed.
12. Isogeotherm – An imaginary line connecting all points within the earth having the same mean temperature.