The Federal Reserve is the most powerful and influential financial institution in the world and it is also one hell of a business.
The Fed, like Newt Gingrich, was hatched in secret one hundred years ago, on a small island off the coast of Georgia. It was created to bring order to a chaotic banking system in the wake of a string of financial crises around the turn of the century. What's gotten the mainstream media buzzing about the bank of late is the fact that, for the first time in it's century-long history, a woman will be running the show. As many have pointed out, incoming chairperson Janet Yellen may in fact become the most powerful woman in the world upon her ascension on February 1st.
The Fed is not quite a government entity but it is not quite a private corporation either; it is something of a hybrid between the two and enjoys the dual benefit of that perception. Its role in the economy is to direct monetary policy (mainly by setting various interest rates), supervise the banking system (LOL), and maintain some semblance of stability in the economy by managing prices and employment to the extent it can.
It also makes a metric ass-ton of money in the process, kicking this cash back upstairs to the U.S. government that permits it to operate.