DNA repair systems are essential mechanisms in cells that fix damage to the DNA molecule. Damage can occur due to various factors, including environmental influences like radiation and chemicals, as well as normal cellular processes. These systems help maintain the integrity of genetic information, preventing mutations that could lead to diseases such as cancer. There are several types of DNA repair mechanisms, including base excision repair, nucleotide excision repair, and mismatch repair. Each system targets specific types of DNA damage, ensuring that errors are corrected efficiently. By repairing DNA, these systems play a crucial role in cellular health and longevity.