Glyph

variant glyphs representing the character a (allographs of a) in the Zapfino typeface.

In typography, a glyph is the shape given in a particular typeface to a specific grapheme or symbol.

The term for the abstract entity represented by a glyph is character: a typographical character may be a grapheme (an element of a writing system), but also a numeral, a punctuation mark, or a pictorial or decorative symbol (such as dingbats, or Unicode's "Miscellaneous Symbols").

Two or more glyphs representing the same grapheme, either interchangeably or context-dependent, are called allographs.

In graphonomics, the term glyph is used for a non-character, i.e: either a sub-character or multi-character pattern.

Etymology

The term has been used in English since 1727, loaned from glyphe in use by French antiquaries (since 1701), from Greek γλυφη "a carving," from γλύφειν "to hollow out, engrave, carve" (cognate to Latin glubere "to peel" and English cleave).

Compare the carved and incised "sacred glyphs" hieroglyphs, which have had a longer history in English dating from the first Elizabethan translation of Plutarch, who adopted "hieroglyphic" as a Latin adjective.

But "glyph" first came to widespread European attention with the engravings and in lithographs from Frederick Catherwood's drawings of undeciphered glyphs of the Maya civilization in the early 1840s.

Typography

In typography, a glyph is a particular graphical representation of a grapheme, or sometimes several graphemes in combination (a composed glyph), or only a part of a grapheme. In computing as well as typography, the term character refers to a grapheme or grapheme-like unit of text, as found in natural language writing systems (scripts). A character or grapheme is a unit of text, whereas a glyph is a graphical unit.

For example, the sequence ffi contains three characters, but can be represented by one glyph, the three characters being combined into a single unit known as a ligature. Conversely, some typewriters require the use of multiple glyphs to depict a single character (for example, two hyphens in place of a dash, or an overstruck apostrophe and period in place of an exclamation mark).

Most typographic glyphs originate from the characters of a typeface. In a typeface each character typically corresponds to a single glyph, but there are exceptions, such as a font used for a language with a large alphabet or complex writing system, where one character may correspond to several glyphs, or several characters to one glyph.

Other uses

• In the Appaloosa Interactive video games Ecco the Dolphin and Ecco: The Tides of Time, a "glyph" is one of several different types of crystalline objects which are usually larger than the protagonist, Ecco. Glyphs may block routes, give a "password" for passing routes blocked by other glyphs, restore Ecco's energy, give hints, or save the game in certain levels.

See also

• Typeface
• Punchcutting
• Character encoding
• Character (computing)