Your CFO wants to move ₦5,000,000 from your operating cash to the sponsor-bank FBO (to pre-fund expected user deposits). Regulator rules, and your own audit policy, require that no single person can authorize a transfer of this size. One human (the 'maker') proposes the transfer; a different human (the 'checker') reviews and approves. Only on approval does the cash actually move. The maker-checker pattern enforces this at the ledger: the proposal is a JOURNAL ENTRY in a 'pending' state, the approval is a SEPARATE entry from a DIFFERENT actor that finalizes it. Two entries, two actors, full audit trail.