The book covers the syllabi of Computer Organization and Architecture for all WBUT colleges. The author has carefully arranged the chapters and topics using Education Technology and Courseware Engineering Principles, with proper planning to help self-paced as well as guided learning. Large numbers of examples, solved problems and exercises have been incorporated to help students strengthen their base in the subject. A number of multiple choice questions have been included with answers and explanatory notes. The basic principles have been explained with appropriate lucid descriptions supported by explanatory diagrams and graphics. The advanced principles have been presented with in-depth explanation and relevant examples.