You can think of any conversation as having three places. First there is the one who is talking, then the one who is listening, and then the one who is only being talked about. That third place is outside the conversation: the person there is pointed at, not spoken to. English collects that position into one fixed set of words — he, she, it, they, and the verb forms that go with them. Everything on this page grows from standing in that third place, whether you are labelling a verb, telling a story, or looking at a game character from behind.
可以想成講話的現場站著三種人。第一個是正在開口的自己，第二個是正在聽的那個人，第三個只是被提到——他不在對話裡，只是被指著談。英文把這第三個位置整理成一組固定的字：he、she、it、they，還有跟著變化的動詞。之後不管是標一個動詞的形式、寫一整本小說，還是打電動時鏡頭站在角色背後，只要視線是落在「被談到的那一位」身上，英文就叫 third person。