The first-generation sequencing refers to the dideoxy terminal termination method. After amplification, the sequence is read by capillary electrophoresis, and the amount of data obtained each time is small; the second-generation sequencing refers to high-throughput sequencing, which uses microbeads or high-density chips while synthesizing Sequencing represents 454, solexa, solid, and high throughput. Data can be obtained at one time. Compared with the third generation, amplification methods are still needed to amplify the signal and then detect after amplification; third-generation sequencing refers to single-molecule sequencing, Mostly based on nanotechnology, without amplification, single-stranded DNA/RNA is directly synthesized, degraded, and directly sequenced through nanopores. The core feature is that there is no need for amplification, so the cost is lower.