A telomere is a protective cap located at the ends of chromosomes, which are structures that carry genetic information. These caps are made of repetitive DNA sequences and help prevent the loss of important genetic data during cell division. Each time a cell divides, telomeres shorten, which is a natural part of the aging process. When telomeres become too short, cells can no longer divide and may enter a state called senescence or die. This shortening is linked to aging and various diseases, including some types of cancer. Research into telomeres is ongoing, as scientists explore their role in aging and cellular health.