GR w/o PO

Hi,

What is GR w/o PO?

iF PO is not there how does the system allows to enter the goods in to the system? As there iis no ref. document?

When do we use the automatic PO function ? Where to customize for the same ?

Any scenario where we use automatic PO?

Does above two business processes related to each other?

Regards,

Shreya.