Fertilization in animals is the process by which a sperm cell fuses with an egg cell to form a zygote, which will then develop into a new organism. This process typically occurs internally in females, where sperm is usually deposited into the female reproductive tract during sexual intercourse. The sperm must then swim to the egg and penetrate its protective layer to fuse with it. Once fertilization occurs, the zygote begins to divide and undergoes further development into an embryo.
