Gametogenesis is the process of formation of male and female gametes, i.e. sperm and eggs respectively. In the case of men, the process is called spermatogenesis and takes place in the testicles. In women, on the other hand, gametogenesis is called ovogenesis and takes place in the ovaries.
This whole process occurs through the division by mesiosis of germ cells, so that their genetic material is reduced by half.
On the other hand, gametogenesis in the male occurs at puberty and in the female it takes place in the third month of fetal development.