How do human sperm come from?

Human sperm is produced by the testis.

Sperm is produced by the testis, mature in the epididymis, and exported through the vas deferens, usually discharged through the urethral orifice. Sperm begins to develop from spermatogonia, gradually transforming into primary spermatocytes, which can divide to produce two secondary spermatocytes, and the second maturation division produces two sperm cells.

Male sperm and female eggs can form fertilized eggs, and fertilized eggs develop into fetuses. Therefore, sperm quality problems can affect fertility.