There's two--One technical distinction that people love to put on Intro Psych exams is that the difference between positive reinforcement and negative reinforcement.

心理学导论的考试中,会经常考到一个术语上的区别,即正强化,与负强化之间的区别。

耶鲁公开课 - 心理学导论课程节选

There were precursors to this, but the SEC forces the difference between public and private securities and this is a very important distinction.

例如证交会强制界定了,公共券商与私募券商之间的差异,这是非常重要的划分

耶鲁公开课 - 金融市场课程节选

This isn't simply a distinction without a difference.

这不是一个简单的没有任何区别的特征。

耶鲁公开课 - 弥尔顿课程节选