One picture holds this word together: something being done for everybody, not for one paying customer. Think of a bus that stops for whoever is waiting, a hospital that opens its door to whoever walks in, a warning message read out to a whole city. Nobody at the counter is asking who paid. From that one picture the word reaches in two directions: outward to the service itself, and back to the people and offices that run it.
Two branches
做給大眾的那件事
這一組直接站在核心畫面上：焦點在「被提供出來的那項服務」。差別只在錢從哪裡來——一邊是稅金，一邊是有人自願不收費。
noun · B1
A service that a government arranges and pays for so that everyone in the country can use it, such as buses and trains, hospitals, schools, water, or garbage collection. It is usually used in the plural.
公共服務
辦這些服務的那個政府
鏡頭從服務本身轉到提供服務的那一邊：辦公室、部門、在裡面上班的人。名字沒有換，只是指向的東西換了。
noun · B2
Work for the government, and also the government departments and their staff taken together as one body. It is normally used with the, as in the public service, and it is not counted.
公職；政府機關