Unicode Explained

Glyphs and Fonts

It is important to distinguish the character concept from the glyph concept. A glyph

is a presentation of a particular shape a character may have when rendered or displayed.

It has even been said that any character is an abstract idea, whereas glyphs for the

character are its different visible manifestations.

Each character we use in English normally has the same basic shape, and glyphs for it

differ in typographic design only. It is obvious that “T” in the Times font represents

the same character as “T” in the Arial font, for example. However, the letter “a” has

two rather different shapes (compare “a” in normal Times font and “a” in Times italic).

When you write literally by hand, you may draw characters differently in different

positions of a word. For example, a word-final “s” may be quite different than a word-

initial “s.” In typewritten or typeset text, or in text displayed or printed on computers,

such distinctions are not made, even in so-called handwriting-style fonts.

In Greek writing, a word-final sigma (ς) is rather different from a normal small sigma

(σ), although they are logically the same character. The first and last letter of the word

σοφός (sophos, “wise”) are the same but are written differently. However, since this

is a special case, character codes usually solve this by encoding them as two separate

characters, and Unicode follows suit, even without defining ...