Genetic engineering and biotechnology are rapidly advancing fields with applications spanning agriculture, medicine, environmental preservation, and manufacturing. This chapter provides an overview of the techniques, applications, and implications of genetic engineering in the twenty-first century. It discusses the evolution of biotechnology from traditional breeding to sophisticated gene editing tools like CRISPR-Cas9. The multidisciplinary nature of genetic engineering is highlighted, with applications in developing enhanced crops, producing recombinant proteins, and creating animal models for studying diseases. The current text also examines the role of genetic engineering in gene therapy and the ethical considerations surrounding germline modifications. Furthermore, it addresses public perception and the regulatory landscape of genetically modified organisms (GMOs), emphasizing the need for science-based risk assessment and effective science communication. The chapter concludes by underscoring the transformative potential of genetic engineering in shaping a sustainable future while acknowledging the importance of responsible innovation.