Epigenetics refers to changes in genetic activity that do not contain changes in DNA sequences but are influenced by environmental and lifestyle factors. With increasing age, these epigenetic changes such as DNA methylation, histone modification, and chromatin remodeling disrupt normal gene regulation, contribute to the development of cellular age, and can lead to disease. Epigenetic watches, a tool for measuring biological age based on DNA methylation patterns, have become an important marker for aging studies. Understanding how epigenetic mechanisms regulate gene expression provides valuable insight into the aging process and opens up new opportunities for interventions that may slow aging and prolong health spans.