The chapter provides a brief overview of the historical events that led to the evolution and diverse applications of genome editing tools. Genome editing tools have evolved from preliminary discoveries of homologous recombination to precise and customizable technologies that have shaped modern biological research and therapeutics development. The initial site-specific genetic modification was performed in yeast and relied on homologous recombination. Its lower efficiency in the mammalian system prompted the development of engineered nucleases such as meganucleases, zinc finger nucleases (ZFNs), and transcription activator-like effector nucleases (TALENs). These tools not only improved the efficiency but also made genome editing highly programmable by exploiting the protein-DNA interactions for site-specific genome targeting. However, it required complex protein engineering. The chapter highlights breakthrough in the genome editing technology with the discovery of the CRISPR/Cas9 system, an RNA-guided tool which significantly improved the simplicity and the efficiency of genome editing, primarily by eliminating the dependence on complex protein engineering. The chapter also discusses the subsequent advancement in the CRISPR/Cas9 technology, such as base editors, prime editors, and RNA-targeting Cas13 effectors and their application across multiple fields, including medicine and agriculture. Overall, the chapter provides critical insights into gene editing technologies and their role in shaping the future biotechnology and precision medicine.