CRR
The cash reserve ratio (or required reserve ratio or only reserve requirement) is a bank regulation that sets the minimum reserves each bank must hold to customer deposits and notes. These reserves are designed to satisfy withdrawal demands, and would normally be in the form of fiat currency stored in a bank vault (vault cash), or with a central bank.
The reserve ratio is sometimes used as a tool in monetary policy, influencing the country's economy, borrowing, and interest rates.
A clearing house is a financial services company that provides clearing and settlement services for financial transactions, usually on a futures exchange, and often acts as central counterparty (the payor actually pays the clearing house, which then pays the payee). A clearing house may also offer novation, the substitution of a new contract or debt for an old, or other credit enhancement services to its members.
I don't think we have clearing houses in our syllabus