How are the twins baby born?

When the sperm of a man enters the ovum of a women the fertilization takes place and the women becomes pregnant. If by chance an ovum divides itself into two parts, the woman delivers two identical children either both boys or both girls. They are called identical or uni-ovular twins. In another possibility if two sperms from the male semen fertilizer two ova of the same woman again two children are born. They are called nonidentical or fraternal twins, because two separate ova have been fertilized. The two children may or may not be of the same sex. They are cases where women have delivered up to ten children at a time.