A Bob (contraction of Blitter object) is a graphical element (GEL) used by the Amiga computer.
Bobs are hardware sprite-like objects, movable on the screen with the help of the blitter coprocessor.
The AmigaOS GEL system consists of VSprites, Bobs, AnimComps (animation components) and AnimObs (animation objects), each extending the preceding with additional functionality.
While VSprites are a virtualization of hardware sprites Bobs are drawn into a playfield by the blitter, saving and restoring the background of the GEL as required.
In contrast to hardware sprites Bobs are not limited in size and number.