Do you mean setspriteposition (1) and setspritepositionbyoffset (2)?
(1) uses the top left corner of the sprite.
(2) uses the centre of the sprite
by default.
You can use either of these, it is personal preference, or the circumstance you are using it in that would decide.
BUT you can also change the offset using setspriteOffset(). The offset can be anywhere, including outside of the sprite itself. In this case you can be a bit more creative. For example you could set an offset that relates to something else on the screen, and use it to rotate the sprite around that other entity.
