There are 3 types of genetic surrogacy circumstances:
Genetic surrogacy or partial surrogacy: This is the most common type of surrogacy. Here the egg of the surrogate mother is fertilized by the commissioning male's sperm. In this way the surrogate mother is the biological mother of the child she carries.
Total surrogacy: Here the surrogate mother's egg is fertilized with the sperm of a donor - not the male part of the commissioning couple.
Gestatory surrogacy or full surrogacy: Here the commissioning couple's egg and sperm have gone through in vitro fertilization and the surrogate mother is not genetically linked to the child.