Is the DWG graphics file format a bitmap format or a vector format? Or can it be either?
I'll restate what has already been written below, in layman's terms:
DWG stores 3D geometry, not images. Geometry is described in terms of points, lines, polygons, etc.
While a 2D vector image can also be described in terms of points, lines and polygons (aka "shapes"), a file format for 3D geometry is never used for storing 2D vector images.
As for bitmaps, they are a completely different kettle of fish and DWG is definitely not related to that.
Thanks for the suggestion to put this in an answer, Rob!