In humans, the immediate product of fertilization is the zygote formed by the fusion of sperm and egg. This zygote undergoes repeated cell divisions white traveling its path from the fallopian tube to uterus, and this group of divided cells is called embryo, which gets embedded in the uterine walls.

Ovum is the infertility egg, and the fetus is the stage of intrauterine life when all body parts can be recognized, and look similar to a mature human being.