Computer Architecture discusses the computer hardware components, their organization and architecture, the way the hardware components operate and the way they are connected together to form the computer system. Computer design is concerned with the hardware design of the computer. Once the computer specifications are formulated it is the task of the designer to develop hardware for the system. Computer design is concerned with the determination of what hardware should be used and how the parts should be connected. This aspect of computer hardware is sometimes referred to as computer implementation. Computer architecture is concerned with the structure and behavior of the computer as seen by the user. It includes the information formats, the instruction set and techniques for addressing memory. The architectural design of a computer system is concerned with the specifications of the various functional modules, such as processors and memories and structuring them together into a computer system. The book is written so that students understand all three basic aspects of computer organization, design and architecture. Various types of computer architecture their CPU Design and organization of different components and overall functionality are described in details.