The GEL types are (in order of increasing complexity):

    vsprites   for virtual sprites.  these are represented by the vsprite
               data structure and implemented with sprite hardware.

    bobs       blitter objects.  these are represented by the vsprite and
               Bob data structures and implemented with blitter hardware.

    animcomps  animation components.  these are represented by the
               VSprite, Bob and AnimComp data structures and implemented
               with blitter hardware.

    animobs    animation objects.  these are used to group animcomps. they
               are not strictly GELs, but are described here.

 simple sprites    bobs and animcomps    vsprites vs. bobs 
 vsprites          animobs