This first edition of Basics of Immunology is a glimpse of immunology. Initially the author prepared a handout on immunology for his preparation for his PhD comprehensive written examination. After the examination he thought to give it in a shape of book with a view that this will be guide for future PhD students who will prepare for their written and oral comprehensive examination. Hopefully this book will be a guide for teachers and students to understand the basic concepts of immunology. Future coming students and my class mates were the major inspiration to write this book. The authors are very grateful to Dr. Tanveer Hussain, Lecturer, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Science who gives the idea to publish the book and helps also in computer composing of this monograph.