Grafeme

Grafeme is a theoretical unit in written language that denotes the smallest element of a writing system able to distinguish meaning within a language. In many linguistic frameworks, grafeme is synonymous with grapheme—the abstract character or symbol that encodes a morpheme or a phoneme. The grafeme is an abstract unit; its concrete realization is a glyph or combination of glyphs. A grafeme may be written with one glyph or with multiple glyphs in different fonts, scripts, or ligatures (for example, ligatures that represent a single sound).

Across languages, grafemes are mapped to phonemes in varied ways; a single grafeme can correspond to several phonemes in different contexts, and a single phoneme can be represented by different grafemes in different languages. This abstraction allows linguistic analysis of orthography separate from pronunciation. The term grafeme is used in some linguistic literature as a synonym for grapheme or as a distinction highlighting the writing-system side of language; usage varies by tradition and language.