出生 (chū shēng) literally means 'to come out and be born' — 出 ('to go out, emerge') combined with 生 ('to live, to be born'). It is a verb describing the moment or event of coming into life. While it can refer to humans, it is especially common in formal, written, or descriptive contexts — such as birth certificates, biographies, news reports, or discussions about animal reproduction. Unlike colloquial alternatives like 降生 (jiàng shēng), 出生 carries neutral-to-formal register and emphasizes factual emergence into existence.

The word functions as an intransitive verb and often appears with time phrases (e.g., 1995年出生), location phrases (e.g., 北京出生), or passive constructions (e.g., 他出生于上海). It does not take an object, and you cannot say *出生一个孩子* — that would be grammatically incorrect; instead, use 生 (shēng) for 'to give birth'. 出生 focuses on the newborn’s perspective: the act of entering the world, not the parent’s action.