A grapheme is the smallest semantically distinguishing unit in a written language
Writing system
A writing system is a symbolic system used to represent elements or statements expressible in language.-General properties:Writing systems are distinguished from other possible symbolic communication systems in that the reader must usually understand something of the associated spoken language to...

. It does not carry meaning by itself. Graphemes include alphabetic letters
Letter (alphabet)
A letter is a grapheme in an alphabetic system of writing, such as the Greek alphabet and its descendants. Letters compose phonemes and each phoneme represents a phone in the spoken form of the language....

, Chinese characters, numerical digit
Numerical digit
A digit is a symbol used in combinations to represent numbers in positional numeral systems. The name "digit" comes from the fact that the 10 digits of the hands correspond to the 10 symbols of the common base 10 number system, i.e...

s, punctuation
Punctuation marks are symbols that indicate the structure and organization of written language, as well as intonation and pauses to be observed when reading aloud.In written English, punctuation is vital to disambiguate the meaning of sentences...

 marks, and the individual symbols of any of the world's writing systems.

It is usual to transcribe graphemes within angle brackets, to show their special status, such as , , .
A glyph is an element of writing: an individual mark on a written medium that contributes to the meaning of what is written. A glyph is made up of one or more graphemes....

s can be concrete representations of the same, abstract grapheme, which means that they are allographs
Allography, from the Greek for "other writing", has several meanings which all relate to how words and sounds are written down.-Allographs as authorship:...