Contrastive distribution
A contrastive distribution in linguistics is a relationship between two or more different elements which can appear in the same environment, but cause a change in meaning when one is substituted for another in that environment. A contrastive distribution is demonstrated with a minimal pair.
Contrastive distribution is distinct from complementary distribution (where different elements appear in different environments and cannot be substituted for one another) and free variation (where different elements, particularly speech sounds, appear in the same environment and can be substituted without changing the meaning).