SAP S/4 INVOICE AND VIMS open txt

Team,

I have a question about VIMS open text invoicing, Ariba invoicing and S/4 procurement invoicing. If an organization has S/4 procurement and Ariba procurement, i am assuming all invoice will be done through via PO Flip/Ariba invoicing. Then what happens to the MIRO in S/4.

1) Do we still use regular MIRO transaction? If so, when we do MIRO invoicing in SAP?

2) If not, if we are doing invoicing in Ariba, then why do we need VIMS open text invoicing?

Just not clear about these different concepts.

Thanks,

N