This document discusses different types of twins and cases of twins throughout history: - According to Greek mythology, humans were originally joined together but were split in two by Zeus. - Jim Lewis and Jim Springer were separated at birth but met as adults and discovered they had remarkably similar lives and names despite being adopted separately. - Conjoined twins Margaret and Mary Gibb were born joined at the hip in 1912 and lived and performed together until they passed away within minutes of each other in 1967. - Rare cases of parasitic twins exist where one twin is incomplete or dependent on the other.