Reconciliation

Reconciliation is the accounting discipline of proving that two independent records of the same activity match. The classic case is bank reconciliation, your ledger of transactions against the bank's statement, but the same pattern covers credit-card statements, vendor invoices against purchase orders, payroll registers, and subledgers against the general ledger.

In practice reconciliation is a structured diff: you align records by a key (a transaction ID, an invoice number, a date-and-amount), then surface what's in one set but not the other, and what matches by key but differs in value. That is exactly a spreadsheet comparison, which is why reconciling 'last month versus this month' or 'our numbers versus theirs' is a natural fit for a cell-by-cell diff with key-column matching.