extreme difference; worlds apart
Idiomatic four-character compound emphasizing a vast, unbridgeable gap between two things, like the distance between heaven and earth or clouds and mud. Often used in formal or literary contexts.
See also: 雲泥
There is a world of difference in their abilities.
There is an extreme gap between these two works.
A more common expression for a vast difference; 天地雲泥 is a stronger, more emphatic variant.
A colloquial phrase meaning 'a difference like heaven and earth'; 天地雲泥 is more literary and condensed.
A four-character compound combining 天地 (heaven and earth) and 雲泥 (clouds and mud), both classical metaphors for extreme contrast. The exact origin is uncertain, but it follows the pattern of Chinese-derived idiomatic expressions.