generation gap

基本解释

Both parents and teenagers must try to bridge the generation gap between them.
父母和青少年双方必须尽力弥合代沟。
We often hear about the “generation gap” that occurs between parents and children when it comes to music, morals, fashion and a host of other things.
我们总能听到父母和孩子之间存在“代沟”，音乐、道德准则、时尚以及很多事情上双方看法都不同。
edu.sina.com.cn
But this divide—what William Frey of the Brookings Institution in Washington, DC, calls “the cultural generation gap”—is very much wider in some states and cities.
美国华盛顿布鲁克林研究所的威廉•弗雷称此种文化代沟在某些州和城市的分化影响更大。

The generation gap in our country is so huge that it's hard to make a compromise."

One of her customers was a 34-year-old IT guy, so maybe they bridged a generation gap.
FORBES: New Company Rents Your Car By The Hour
Interestingly, the revenue generation gap between iPad and iPhone has been narrowing as well.
FORBES: Android Apps Closing The Revenue Gap With iOS Apps Rapidly
And there is a yawning generation gap: 55% of 18-29-year-olds support gay marriage, but only 21% of those over 65.
ECONOMIST: Gay marriage

If you refer to the generation gap, you are referring to a difference in attitude and behaviour between older people and younger people, which may cause them to argue or may prevent them from understanding each other fully.