What is a Phoneme?

A phoneme is the smallest unit in the sound system of a language that can be identified as distinct from any other unit of sound. A phoneme is a minimal unit that serves to distinguish between meanings of words.

A pair of words like kátur and gátur that differ only in one "phone" is called a minimal pair.

Here are examples of the phonemes /r/ and /l/ occurring in a minimal pair:

rip
lip

In the field of comparative linguistics the comparison of phones is important in efforts to trace connections between languages. Comparative linguistics is the study of similarities and differences between languages, in particular the comparison of related languages with a view to reconstructing forms in their lost parent languages.

Related reading: Glossary of Linguistic Terms; Phoneme Study Pinpoints Origin of Modern Languages; Comparative Linguistics