Bitmap Class
BitMap A file containing a bitmap to use. Any datatypes object can be loaded. The file may use any palette and will be mapped into the current screen's colors.

If more than one bitmap object exists and their BitMap attributes are identical, then the bitmap will only be loaded into memory once. If the filenames are different, even if they point to the same file, then the bitmap will be loaded multiple times.

Mask If set, this bitmap must be a 2 plane image the same size as the primary bitmap. Pixels from the primary bitmap are displayed only where this bitmap is set (white). Otherwise, the background is displayed. This allows for transparent areas in images.

An image with... ...and without a mask.