CRISPR-Cas9 has revolutionized genetic engineering and therapeutic applications with its unprecedented precision and efficiency in genome editing. This review explores the CRISPR-Cas9 system, detailing its mechanisms and diverse applications in genetic engineering, agriculture, and medicine. The technology's advantages, such as cost-effectiveness and versatility, are highlighted alongside its challenges, including off-target effects and ethical considerations. Recent advancements, including next-generation CRISPR systems, base and prime editing, and innovative delivery methods, are discussed, showcasing the continuous evolution of CRISPR technology. Future directions suggest significant impacts on personalized medicine, complex disease treatment, and sustainable agriculture. Ethical and regulatory considerations are emphasized to ensure responsible use of CRISPR-Cas9. As research progresses, CRISPR-Cas9 remains at the forefront of biotechnology, offering new solutions to critical scientific and medical challenges.