A grapheme represents the smallest unit of written language that corresponds to spoken sounds in reading and writing systems. These visual symbols include individual letters, letter combinations, or characters that represent specific phonemes in written text. Learning what is a grapheme becomes essential when understanding that the letter “b” is a single grapheme, while “ch” functions as a two-letter grapheme representing one sound. Dr. Matthew Lynch emphasizes that grasping this concept is fundamental for literacy development, as students must connect these written symbols with their corresponding sounds. This grapheme-phoneme relationship forms the foundation of phonics instruction, enabling readers to decode unfamiliar words and develop fluent reading skills.