Explanation
The confirmation control key determines the sequence of required confirmations and whether a confirmation is a prerequisite for a goods receipt. It also controls the output type and the transmission medium for the confirmations1 References: SAP Help Portal - Confirmation Control Key

Explanation
Supplier consignment is a special procurement process in which the materials are stored at your premises but are still owned by the vendor. What you must do when using supplier consignment are:
Create consignment info records, which contain information about the conditions and delivery data for a consignment material from a specific vendor.
Settle liabilities resulting from consignment stock withdrawals, which means that you pay the vendor for the materials that you have consumed from the consignment stock. References: SAP S/4HANA Sourcing and Procurement | SAP Learning, Course S4520, Unit 4, Lesson 1.