Explain the process of how the Fed changes interest rates and how those changes encourage an appropriate increase or decrease in spending in the economy?

Whatch this video: https://www.youtube.com/watch?v=xfwAqGqT2_Q&feature=youtu.be Hosted by radio and television news veteran Charles Osgood, this video gives an overview of the Federal Reserve System from its founding in 1913 to the technological innovations of 21st century banking. Explain the process of how the Fed changes interest rates and how those changes encourage an appropriate increase or decrease in spending in the economy?