Telomeres are protective DNA–protein caps located at the ends of each chromosome. They consist of repetitive sequences that do not code for genes but instead act as buffers during DNA replication. Every time a cell divides, telomeres shorten slightly, because the replication machinery cannot fully copy the ends of linear DNA. When telomeres become too short, the cell either stops dividing or undergoes programmed death. Specialized enzymes like Telomerase can extend telomeres in certain cells. Their main purpose is to preserve genetic stability, prevent chromosome fusion, and regulate cellular lifespan, linking them closely to aging and disease processes.