This book covers semiconductor memory technologies from device bit-cell structures to memory array design with an emphasis on recent industry scaling trends and cutting-edge technologies. The first part of the book discusses the mainstream semiconductor memory technologies. The second part of the book discusses the emerging memory candidates that may have the potential to change the memory hierarchy, and surveys new applications of memory technologies for machine/deep learning applications. This book is intended for graduate students in electrical and computer engineering programs and researchers or industry professionals in semiconductors and microelectronics.