ContourGraphics[array] is a representation of a contour plot.
array must be a rectangular array of real numbers, representing values.
The following options can be given:
ContourGraphics[g] converts DensityGraphics and SurfaceGraphics objects to ContourGraphics. The resulting graphics can be rendered using Show.
Graphics[ContourGraphics[ ... ]] generates a representation in terms of an ordinary Graphics object.
ContourGraphics is generated by ContourPlot and ListContourPlot.
See The Mathematica Book: Section 2.9.1 and Section 2.9.7.
See also: ListContourPlot, DensityGraphics.