This review traces the history of DNA sequencing technology, highlighting the evolution from early methods to modern sequencing techniques. The first generation of DNA sequencing, developed in the 1970s, relied on methods such as Sanger's chain-termination technique and the Maxam-Gilbert chemical cleavage method. These methods allowed for the sequencing of short DNA fragments and laid the foundation for later advancements. The second generation of sequencing, emerging in the late 1990s and early 2000s, introduced high-throughput technologies like 454 sequencing and Illumina's Solexa method, which enabled the rapid sequencing of large genomes. These technologies significantly reduced the cost and time required for DNA sequencing, making it more accessible for research and clinical applications. The third generation of sequencing, developed in the 2010s, includes single-molecule real-time (SMRT) sequencing and nanopore sequencing, which offer longer read lengths and real-time sequencing capabilities. These advancements have transformed DNA sequencing, making it a fundamental tool in biological research, enabling the study of complex genomes and facilitating the development of new diagnostic and therapeutic approaches. The history of DNA sequencing reflects the continuous innovation and improvement in molecular biology techniques, driving progress in genomics and biotechnology.This review traces the history of DNA sequencing technology, highlighting the evolution from early methods to modern sequencing techniques. The first generation of DNA sequencing, developed in the 1970s, relied on methods such as Sanger's chain-termination technique and the Maxam-Gilbert chemical cleavage method. These methods allowed for the sequencing of short DNA fragments and laid the foundation for later advancements. The second generation of sequencing, emerging in the late 1990s and early 2000s, introduced high-throughput technologies like 454 sequencing and Illumina's Solexa method, which enabled the rapid sequencing of large genomes. These technologies significantly reduced the cost and time required for DNA sequencing, making it more accessible for research and clinical applications. The third generation of sequencing, developed in the 2010s, includes single-molecule real-time (SMRT) sequencing and nanopore sequencing, which offer longer read lengths and real-time sequencing capabilities. These advancements have transformed DNA sequencing, making it a fundamental tool in biological research, enabling the study of complex genomes and facilitating the development of new diagnostic and therapeutic approaches. The history of DNA sequencing reflects the continuous innovation and improvement in molecular biology techniques, driving progress in genomics and biotechnology.