A contour line is a drawing that is just an outline of an object, with no shading. I'm not sure if this answered your question, but it's a start.
parallel lines
Hachured contour lines are contour lines with ticks pointing downslope that indicate a depression on a topographic map.
The numbers of contour lines indicate altitude or elevation along that line.
If the contour lines on a topographic map have wide spaces in between and are further apart then the terrain is relatively flat. If the contour lines are close together then the terrain forms a steep slope.
Maps can show elevation with contour lines
isolines
A contour line represents a certain vertical height above the the contour line shown drawn below. Contour lines are a means of representing 3D hills and mountains on a 2D flat paper. Maps should show the height between contour lines: 50 metres between contour lines is common.
A contour line represents a certain vertical height above the the contour line shown drawn below. Contour lines are a means of representing 3D hills and mountains on a 2D flat paper. Maps should show the height between contour lines: 50 metres between contour lines is common.
parallel lines
Contour lines are used in Topography to show the elevation of the land on a map. When looking at a map the contour lines look very similar to how a calm lake would appear.
The darker contour lines on map are called index contour lines. Numbers that indicate elevations are often written on these lines.
Hachured contour lines are contour lines with ticks pointing downslope that indicate a depression on a topographic map.
Index contour lines are thicker and usually have their elevation labeled. They help users quickly identify key elevations on a topographic map. In contrast, regular contour lines show the shape and elevation of the land but do not have specific labels.
Contour maps show the shape and elevation of the land by using contour lines to represent points of equal elevation. This allows viewers to visualize topography and understand the natural landscape of a given area.
The difference in elevation between two contour lines that are side by side is the contour interval. The contour interval is the vertical distance between two adjacent contour lines on a topographic map.
The definition of a contour interval is the difference in elevation between two consecutive lines.
If contour lines on a map are spaced closely together, it indicates a steep slope, possibly an uphill area. Conversely, if contour lines are spaced far apart, it suggests a gentle slope or a downhill area. By observing the pattern of contour lines and their spacing, you can determine the direction of the terrain—whether it's going uphill or downhill.