Process Order - Business diference between release x confirm

Hi SAP gurus

I am a beginner on SAP and I am working on Manufacturing / PP

Please, someone could explain me what the business diference among:

1) COR1 - Create Process Order

2) COR6 - Release Process Order

3) CORK - Process Order Confirmation

4) COR7 - Create Process Order from Planning Order

Is Release PO the same as PO Confirmation ? Can I release PO from other SAP transaction ?

does COR7 release the PO already ? Or I have to release after ?

Thanks in advance !