The term contrast is used to describe the situation where the difference between two phonetically distinct sounds is also phonologically relevant in a language, in the sense that the difference between the sounds is used to distinguish words in that language. For example, there is a contrast between voiced and voiceless plosive sounds in English, but not in the Australian language Dyirbal, which has voiced and voiceless plosives phonetically, but the difference is not phonologically relevant.

Also called distinction or opposition.