Stages of spermatogenesis involve certain cell types entering different processes, such as the primary spermatocyte which uses meiosis I, two secondary spermatocytes that use meiosis II, or four spermatids using spermiation.
The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid cells. The entire process of spermatogenesis can be broken up into several distinct stages, each corresponding to a particular type of cell in humans. 
