Look up covariance or contravariance in Wiktionary, the free dictionary.
Covariance and contravariance may refer to:
- Covariance and contravariance of vectors, in mathematics and theoretical physics
- Covariance and contravariance of functors, in category theory
- Covariance and contravariance (computer science), whether a type system preserves the ordering ≤ of types
- An informal synonym for invariance (physics)