The DEM capture was produced from 2002 orthophoto at 1:10,000. It includes elevations on a 40m grid spacing together with break lines along all visible terrain impacting features (road edges, drainage, etc.) The DEM is a representation of a topographical surface, specifically a regular grid of spot heights and break lines (noticeable changes in slope). The file is available in UTM NAD83 in DWG format. The DEM does not contain contours, but they can be generated from the DEM.
The contour file is a separate product that is derived from the DEM. The contour interval is 1m.
If you have the software to generate contours from the DEM, then all you would require is the DEM and produce the contours yourself. The contours became available for those users who do not have this software ability.