Hi Sharu,
Maintain account assignment categories ,which is part of MM customization where MM consultant can create the account assignment categories ,which will enter while creating the PR / PO's ,if materials procured against sales order / cost center / Internal order / Projects like that.
If you are not enter any account assignment category and item category while creating the PO > Balance sheet account getting Debited along with GRIR Clearing account getting credit.
If you procure materials against account assignment category & consumption indicator as V.
Profit and loss account getting Dr along with GRIR clearing account getting credit.
Significance is :- Nature of postings will change as mentioned above depends upon consumption indicator
Second Query :- Both GR's are same. One from against Purchase order and Other is against production order. Production order will create for to produce the goods internally and Purchase order will create for procure the materials externally.
Regards
Mani