Anyone can ejaculate. It is the point where people reach climax or sexual peak and release liquid from their genitals. For people who have a penis, this is the semen. The semen contains sperms that can impregnate people with a vulva in case of penetrative vaginal sex and the semen is released inside the vagina or around the vulva. Sometimes there is a possibility to ejaculate without reaching orgasm. Ejaculation is usually pleasurable and not painful or uncomfortable.
Sources:
https://my.clevelandclinic.org/health/articles/10036-erection-ejaculation-how-it-occurs
https://www.verywellhealth.com/facts-about-ejaculation-ejaculate-2329073
https://www.plannedparenthood.org/learn/teens/puberty/whats-deal-erections-ejaculation-and-wet-dreams
https://www.healthline.com/health/semen-vs-sperm