The role of telomeres in aging is significant, as they protect the ends of chromosomes from deterioration. Telomeres shorten with each cell division, which limits the number of times a cell can divide—a process known as the Hayflick limit. Once telomeres become critically short, cells can enter a state called senescence or undergo programmed cell death, leading to the signs of aging at the organism level. Understanding telomere biology has important implications for studying age-related diseases and potential anti-aging therapies.