Genetic engineering, or genetic modification, involves laboratory techniques to alter an organism's DNA, from changing single base pairs (A-T or C-G) to deleting or adding DNA segments. This vast field includes gene manipulation in plants, animals, and other organisms. The first edition of this textbook provides a foundational understanding of genetic engineering, serving as an introductory resource for undergraduates in biotechnology, genetics, and molecular biology. Drawing on credible sources, it’s designed as a valuable tool for students. The authors welcome readers’ feedback and suggestions for enhancing future editions, aiming for an engaging learning experience.