Grapheme

The smallest unit of a writing system, typically a letter or group of letters that represents a single phoneme (sound). For example, the word "ship" contains three graphemes: <sh>, <i>, and <p>. Understanding grapheme-phoneme correspondence — how written letters map to spoken sounds — is fundamental to reading acquisition and is a key area of difficulty for people with dyslexia. Many assistive technology interventions for dyslexia focus on strengthening grapheme-phoneme connections.