A "twin" refers to one of two offspring produced by the same pregnancy. Twins can be either identical, sharing the same genetic material and often looking very similar, or fraternal, developing from two separate eggs fertilized by two different sperm. This fascinating phenomenon occurs in humans and many animals, making twins a subject of interest in both science and culture. Twins often share a special bond, sometimes described as a unique connection that goes beyond friendship. They may have similar interests and experiences, and many people enjoy learning about famous twins like Mary-Kate and Ashley Olsen or Tia and Tamera Mowry. This special relationship can lead to a lifetime of shared memories and support.