Telomeres are the ends of chromosomes, which have an essential role in protecting their integrity in the process of cellular replication. One common analogy is that they are like the plastic caps at the end of shoelaces which keep the laces from unraveling. Telomeres are formed by repeats of a DNA sequence, along with associated proteins.
The function of telomeres is to protect chromosome ends from chromosome fusions and degradation, therefore, ensuring the proper functionality and viability of cells.