Thanks for your questions. Lots of people have questions about sperm and semen, and how they are made.
Sperm is the male gamete or sex cell. Sperm contain the genetic information of sex-assigned at birth males.
Semen is fluid that contains both sperm and seminal fluid (a whitish fluid). Seminal fluid is made by the seminal vesicles and prostate gland.
Testicles have very small tubes called seminiferous tubules; this is where sperm develop. As sperm cells mature and develop, they move through the epididymis (a coiled tube). Sperm cells finish development in the epididymis. They are also stored in the epididymis until ejaculation, when they move to the vas deferens (or sperm duct).
The vas deferens and seminal vesicle come together at the ejaculatory duct. This is where sperm and seminal fluid meet to form semen. The ejaculatory duct then empties into the urethra (urine tube). The urethra ends at the tip of the penis.