What does “the advent of” mean in English?

Before chairs existed, most people squatted on the ground — totally normal. In this clip, a fitness instructor points out that people could do a deep squat “before the advent of chairs.” That phrase just means “before chairs arrived.” It is a formal way to mark a turning point in history. One useful detail: small “a” advent means arrival; capital “A” Advent is the period before Christmas.

The fitness instructor explains that the deep squat used to be normal for everyone: “before the advent of chairs, before everybody had western style toilets… you had to be able to do this.” Here “the advent of chairs” simply means the time when chairs arrived and became common. The phrase is always followed by “of,” and it points to a turning point: “the advent of the internet,” “the advent of smartphones,” “since the advent of air travel.” It fits formal, written English — a news article or an essay, not a casual chat. In everyday speech, people are more likely to say “before chairs came along” or “since the internet started.”