Writing systems break text into reusable units. A grapheme is the smallest functional unit of a writing system, roughly analogous to the phoneme in speech.

In alphabets, graphemes correspond largely to letters, though digraphs may function as single graphemes. Other systems use characters for syllables or morphemes. Graphemes are abstract; their shapes appear as glyphs that vary by font and hand.

Orthographic reform, literacy teaching, and digital encoding all depend on clear grapheme analysis. Confusing graphemes with phonetic values misrepresents how writing relates to speech. Typologists compare grapheme inventories when classifying writing systems.

• Smallest functional unit of a writing system
• Realized visually by glyphs
• May represent sounds, syllables, or morphemes
• Central to orthography and literacy