Goods receipt confirms stock arrived (receipt note / GRN). Purchasing → Goods receipt.
From a PO: Receive → enter qty (partial OK; Fill remainders) → Confirm receipt. Status: not received → partially → fully.
Save draft does not change stock and creates no journal entry. Receive (confirm) updates stock and creates the accounting journal entry (when receipt cost > 0).
Extra costs: allocate → New warehouse price. Cost math: Cost price calculation.
Link invoice: Link / Create new / Remove link; or Create invoice (N).
Related: Purchase orders, Purchase invoices.