Protectionism is whereby nations aim to prevent or restrict the supply of goods coming into the country. In other words, it employs various tools to prevent international competition competing with local businesses.
The discount rate is the interest rate by which the central bank charges commercial banks to borrow money or cover short-term liabilities. In other words, the central bank lends money to the likes of Goldman Sachs, and in turn, they pay interest of that loan. The interest paid is known as the discount rate.