Internal fertilization

External fertilization

It involves the fusion of the male and the female gamete inside the female body.

It involves the fusion of the male and the female gamete outside the female body.

Chances of the survival of the offspring are more. Therefore, a small number of eggs are produced.

Chances of survival of the offspring are less. Therefore, a large number of eggs are produced.

Humans, cows, hens are organisms showing internal fertilization.

Fish, frog, starfish are organisms showing external fertilization.