Fertilization involves the fusion of egg and sperm to form zygote.Fertilization process differs in a way which occurs naturally within the body or through the reproductive technologies outside the body, but the overall outcome or product in both cases is Zygote.In case of humans, Fertilization occurs in the end of the fallopian tube away from the uterus. After ejaculation from a male, millions of sperm start swimming upstream towards the fallopian tubes with the mission to fertilize an egg in the female body. Lucky one few sperm reaches the egg and trying to penetrate through the membrane. Finally one sperm fertilizes the egg generating a zygote. Approximately four days after fertilization, the zygote divides into blastocyst which finally implants itself in the uterine wall. Thus, signalling pregnancy in females.