天渊

tiān yuān zhī gé

天渊之隔

poles apart

zhè liǎng rén de shī zuò xiāng qù tiān yuān

这两人的诗作相去天渊。

There is a world of difference between the two poets.

zì xìn yǔ zì dà yǒu zhe tiān yuān zhī bié

自信与自大有着天渊之别。

There is a huge difference between being confident and being conceited.