Halfwidth and fullwidth forms

A command prompt (cmd.exe) with Korean localisation, showing halfwidth and fullwidth characters

In CJK (Chinese, Japanese, and Korean) computing, graphic characters are traditionally classed into fullwidth and halfwidth characters. Unlike monospaced fonts, a halfwidth character occupies half the width of a fullwidth character, hence the name.

Halfwidth and Fullwidth Forms is also the name of a Unicode block U+FF00–FFEF, provided so that older encodings containing both halfwidth and fullwidth characters can have lossless translation to and from Unicode.