In typography, a glyph is an elemental symbol within an agreed set of symbols, intended to represent a readable character for the purposes of writing. Glyphs are considered to be unique marks that collectively add up to the spelling of a word or contribute to a specific meaning of what is written, with that meaning dependent on cultural and social usage.
Some characters such as "æ" in Icelandic and the "ß" in German language may be regarded as glyphs, yet they were originally ligatures, but over time have become characters in their own right, and these languages treat them as separate letters. However, a ligature such as "ſi", that is treated in some typefaces as a single unit, is arguably not a glyph as this is just a quirk of the typeface, essentially an feature, and includes more than one grapheme. In normal handwriting, even long words are often written "joined up", without the pen leaving the paper, and the form of each written letter will often vary depending on which letters precede and follow it, but that does not make the whole word into a single glyph.
The word hieroglyph (Greek for sacred writing) has a longer history in English, dating from an early use in an English to Italian dictionary published by John Florio in 1598, referencing the complex and mysterious characters of the Egyptian alphabet. The word glyph first came to widespread European attention with the engravings and lithographs from Frederick Catherwood's drawings of undeciphered glyphs of the Maya civilization in the early 1840s.
A glyph is "the specific shape, design, or representation of a character". It is a particular graphical representation, in a particular typeface, of an element of written language, which could be a grapheme, or part of a grapheme, or sometimes several graphemes in combination (a composed glyphFor example, the sequence ſi contains two characters, but can be represented by one glyph, the two characters being combined into a single unit known as a ligature. Conversely, some older models of require the use of multiple glyphs to depict a single character, as an overstruck apostrophe and full stop to create an exclamation mark.). If there is more than one allograph of a unit of writing, and the choice between them depends on context or on the preference of the author, they now have to be treated as separate glyphs, because mechanical arrangements have to be available to differentiate between them and to print whichever of them is required. The same is true in computing. In computing as well as typography, the term "character" refers to a grapheme or grapheme-like unit of text, as found in natural language ( scripts). In typography and computing, the range of graphemes is broader than in a written language in other ways too: a typographical font often has to cope with a range of different languages each of which contribute their own graphemes, and it may also be required to print other symbols such as . The range of glyphs required increases correspondingly. In summary, in typography and computing, a glyph is a graphics unit.