Hi Ravichand,
The CRM one order model means that all transactions (sales orders, activities, contracts, activities, ...) are modelled in the same way.Basically CRM One Order Documents they all have a common structure to handle the data.It is possible that all transactions have different fields but the basic structure is same for every transaction.
we have only one TCode i.e CRMD_ORDER(which is used to create, delete and edit transactions), so we have one HEADER table i.e. CRMD_ORDERADM_H and one ITEM table ie. CRMD_ORDERADM_I these two tables contains the Transactional data of all orders.
What is the advantage of this? Maintainability and stability. This also implies that no matter what transaction you want to edit you can always use the same function modules (CRM_ORDER_MAINTAIN, CRM_ORDER_READ, ....)
Thanks