Commercial banks accept deposits and provide loans to earn a profit from the interest rate spread. They create credit in the economy through the process of lending out deposits while maintaining required reserve ratios. The Reserve Bank of India uses various monetary policy tools like repo rates, cash reserve ratios, and statutory liquidity ratios to regulate money supply and credit creation in order to achieve economic objectives. It has established a monetary policy committee to decide interest rates, replacing the previous system of the RBI governor making decisions with input from the monetary policy department.