Your author decided to write this book about Dark Matter when observations from the CERN reported that evidence of Dark Matter, which consists of about 25% of the mass of the Universe, had been found early in the year 2013. I found there was a tremendous amount of research going on about the Cosmology of our Universe including such items as Dark Matter. I performed extensive research on the Internet of the research taking place to discover what Dark Matter is. When I was a student at Caltech for my BS in Physics and at USC for my PhD in EE, Internet did not exist. It is exciting that Internet makes it easy to transfer knowledge quickly and efficiently. Search Engines such as Google and Yahoo make it easy to research what is known about such matters as Dark Matter. This book presents what I learned about Dark Matter and what it is.