Fertilization in humans is the process by which a sperm cell from a male combines with an egg cell from a female to form a new individual. This process occurs within the female reproductive system, specifically within the fallopian tubes, which are the tubes that connect the ovaries to the uterus.

Fertilization typically occurs during sexual intercourse, when sperm are ejaculated into the female reproductive tract through the penis. The sperm then travel through the cervix, the opening of the uterus, and into the fallopian tubes, where they may encounter an egg that has been released from the ovary during ovulation.

If a sperm cell successfully penetrates the outer layer of the egg, it undergoes a process called fertilization, in which its genetic material combines with that of the egg to form a zygote. The zygote then begins to divide and multiply rapidly as it moves down the fallopian tube towards the uterus.

Once the zygote reaches the uterus, it may implant itself into the lining of the uterus and begin to grow and develop into a fetus. If implantation does not occur, the zygote will pass out of the body during menstruation.

Fertilization is a critical process in human reproduction, as it allows for the creation of new individuals and the continuation of the species. It also results in the unique combination of genetic traits from both parents, which gives rise to the diversity of the human population.