Zero interest-rate policy is a policy of keeping the interest rate (the amount of money you pay or receive when you lend or borrow money) as close to zero as possible. This means that when banks or other financial institutions lend money, they won't get much money in return. This can help the economy by making it easier for businesses and consumers to borrow money and spend it on things like new homes, businesses, or products - all of which help the economy to grow.