事业(shì yè) - career, life's work, undertaking, cause in Mandarin

事业 (shì yè) is the big version of work: a career taken as a whole, a life's work, a cause. It has weight and a touch of idealism, which is why it turns up in obituaries, speeches and the standard phrase 事业成功 (a successful career).

The three neighbours are worth separating. 工作 is the job you do on Monday, the concrete task or post. 职业 is the profession you would tick on a form, teacher or engineer. 事业 is what all of that adds up to over decades. Ask a Mandarin speaker 你的工作是什么 and you get a job title; ask about their 事业 and you have asked something rather bigger.

It also names whole public sectors, as in 教育事业 and 医疗事业, where English would say "the education sector". And the compound 事业单位 is a specific institutional category in China, the state-funded public bodies that are neither government departments nor private firms, so do not read it as "career unit".