The characters 书记 (shūjì) combine to mean “secretary,” literally someone who “writes and records.” By adding 总 (zǒng) in front, the title is elevated to “General Secretary” or “Chief Secretary,” indicating the leader of all other secretaries and the party as a whole.
The title 总书记 (zǒngshūjì) is the key to understanding power in China. China operates under a “party-state” system, where the Communist Party's authority is supreme and fused with the government's. The leader of the Party is therefore the leader of the country. A common point of confusion for Westerners is the comparison between China's 总书记 and the U.S. “President.”
The current leader, Xi Jinping, holds three main titles: 1. 总书记 (zǒngshūjì): General Secretary of the CCP (most powerful role). 2. 国家主席 (guójiā zhǔxí): State Chairman, translated as “President” (head of state, largely ceremonial). 3. 军委主席 (jūnwěi zhǔxí): Chairman of the Central Military Commission (controls the armed forces). Of these, 总书记 is the title that signifies his core authority. This reflects the political value of collective party leadership (at least in theory) and the absolute centrality of the Party in Chinese society.
The term 总书记 is used almost exclusively in formal and official contexts.
The term carries a neutral to respectful connotation and is highly formal. You would not use it to refer to a secretary in an office.