In this book, I respond to the need for explanations of UAPs/UFOs, as presented by the Report from the Office of the Director of National Intelligence. I work within the Framework of the Pentagon's statement that UAPs are real objects with advanced intelligently controlled technologies, which are not ours (US). I present explanations of the Physics of UFOs/UAPs and how they work. I analyze and explain UAPs' flight characteristics. I present explanations for the observables listed by the National Intelligence Director's Report. I address and refute the hypothesis that UAPs are advanced hypersonic drones from Russia or China. I review and address the National Security as well as air safety concerns. I present case evidence and historical data supporting the hypothesis that some UFOs/UAPs are advanced technologies that do not seem to originate from Earth. It is evidence that may be conducive to the discovery, the realization that we are not alone in the Universe. This book is also intended to be used for additional reading in Astronomy and Physics classes.