Twin siblings are two children born at the same time from the same pregnancy. They 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. Identical twins arise from a single fertilized egg that splits, while fraternal twins come from two separate eggs. Twin siblings often share a unique bond, growing up together and experiencing many life events side by side. They may have similar interests and friendships, but they can also develop their own individual personalities. This close relationship can lead to strong emotional connections throughout their lives.