clear difference

hi,

i need to know the difference below. hope can reply by point.

1) what is the difference for fb05 (post with clearing) VS f-03 (clear gl) , f-32(clear cust), f-44 (clear vendor). i mean all also clear so what is the difference?

2) under what circumstances i need to use fb05 or f-03, f-32, f-44.

3) f-03, f-32, f-44 also do post and clear right?

4) fb05 and f-02 any difference? i notice fb05 with doc type SA whereas f-02 doc type field no default. so wht is the difference?

thanks