Central bank reserves
From ACT Wiki
Banking - central banks - monetary policy.
Deposits maintained by non-central bank monetary financial institutions with their central bank in the latter's capacity as 'the bankers' bank'.
These deposits are current account balances in favour of the depositing institution, effectively cash deposited at the central bank.
Central banks may require institutions to maintain minimum balances with the central bank, in which case balances in excess of the minimum are known as 'excess reserves'.