'生日' literally combines '生' (shēng), meaning 'to be born' or 'life', and '日' (rì), meaning 'day'. Together, they form the compound noun 'birthday' — the day a person is born. It is used exclusively for human birthdays, not for anniversaries of events or non-human entities. The term carries warm, personal connotations and is central to celebrations involving family, friends, cakes, gifts, and well-wishes.

In Chinese culture, birthdays are marked with varying traditions depending on age and region: younger people often celebrate with parties and presents, while elders may receive symbolic foods like longevity noodles. '生日' is neutral in register — appropriate in both casual speech and formal invitations. Unlike English, Chinese doesn’t use possessive forms (e.g., no equivalent of 'my birthday'); instead, context or pronouns clarify ownership (e.g., '我生日' means 'my birthday').