However, orgasms are important to a lot of men and their partners, and for a lot of people, ejaculation marches in lockstep with an orgasm. This isn't medically true, but it can be difficult to separate male orgasm from male ejaculation. Even in discussions with doctors and other sexual health professionals, it's easy to conflate the observable production of sperm, or ejaculation, with its common contextual counterpart: the male orgasm.
That being said, there are important medical distinctions between the two, and the most relevant distinctions apply to the lack of either or both.
Anejaculation is the inability to ejaculate semen; a man can produce sperm but can't expel them with ejaculate, because there is none. Anorgasmia is the inability to achieve orgasm.