Identical twins are siblings who develop from a single fertilized egg that splits into two embryos. This means they share the same genetic material, making them genetically identical. They often look very similar, with the same physical features, such as hair color and eye color, but they can still have slight differences due to environmental factors. Identical twins are also known as monozygotic twins. They typically share the same placenta during pregnancy, which can lead to unique health considerations. While they may have similar personalities and interests, each twin is still an individual with their own experiences and traits.