Questions on Inter-company and Cross-company sales ordering process..

Hi,

I understood the delivery plant and the sales org. is not in the same company code might be the process, but i want to know some details especially in SAP system how it is realized and processed, hope could kindly help me on below questions!! thanks!!

1)what is the difference between inter-company sales and Cross-company sales??

2)What is the general document flow and config. when in below 2 cases:

Suppose the 2 company code under same sap client system, then what kinds of company code,plant config within the system for inter-compan and cross-company, and finally what kind of document flow will it be in the system.

Suppose the 2 company code is under diff sap system, then what kind of doc flow in each sap system for inter-company and cross-company sales process???

Thank you very much!!!!