Hi,
An accounting transaction is complete when there is atleast one debit and corresponding credit entries to that transaction. This example will explain the Offsetting Account:
Purchased goods Accounting Entry:
Material Account Dr
GR/IR Account Cr
In this case, Material Account is the Offsetting Account for GR/IR Account and GR/IR Account is the offsetting Account for Material Account.
Please let me know if you need further clarification.
Thanks
Ekhlaque