The first quantum revolution brought us the great technological advances of the 20th century—the transistor, the laser, the atomic clock and GPS, the global positioning system.  We now realize that this 20th century hardware does not take full advantage of the power of quantum machines. A second quantum revolution is now underway based on our relatively new understanding of how information can be stored, manipulated, and communicated using strange quantum hardware that is neither fully digital nor fully analog.   This talk will give a gentle introduction to the basic concepts that underlie this quantum information revolution and describe major challenges as well as recent remarkable experimental progress in the race to build quantum machines for computing, sensing and communication.