An alphabet is a type of writing system that uses a set of letters to represent a language visually. Each letter represents a different sound, and when combined together following a certain order specific to each language, they form syllables, words, and sentences.

Across the world and throughout history, many languages have used alphabetical systems (Greek, Arabic, Hebrew, etc.). As of today, the Latin script is being used for the largest number of languages, with many different sets of alphabets, varying in number of letters depending on the needs of the language (i.e., both English and Spanish use the Latin script, but they have different alphabets).

In East Asian typeface design (Chinese, Japanese, and Korean), characters (commonly called Hanzi) are settled in a squared frame, the same for all characters of one typeface.

The glyph surface (字面 in Chinese, literally ‘face of the character’) is the area occupied by the character in its square.