There are two types of reproduction: sexual and asexual. Sexual reproduction involves both male and female reproductive organs and gametes fusing during fertilization. The male organs produce sperm and the female organs produce eggs. Fertilization occurs when a sperm fuses with an egg in the fallopian tubes, forming a zygote that develops into an embryo and fetus. Fertilization can be internal, occurring inside the female body as in humans, or external, occurring outside the body as in fish. Asexual reproduction requires only one parent and produces offspring that are genetically identical through processes like budding.