FUNCTION

For many writing systems (but not all), spaces separate words. Like punctuation symbols, they bring rhythm and clarity to a text and help with the reading experience. In the Latin script, several spaces with different widths are used for various situations (see Typographic Rules below).

HISTORY

In Ancient Latin, Roman capitals had no spaces between words. In some monuments, dots could be placed at middle height to help identify the words. In Europe, with the adoption of the Latin script, they started to appear in calligraphed manuscripts to help the readers identify the different words.

During the metal type printing era, blank pieces of lead were used as spaces between words. There were multiple widths for word spaces to help arrange text lines with precise length (em space, thin space, etc.). They lead to various rules in various languages and typographic traditions.

Nowadays, texts in the digital realm still make use of a variety of spaces for different situations in different languages, and also to offer different typographic options.

DESIGN

Spaces shouldn’t be too wide or too narrow. In Latin script based languages, a common convention is to set the width of the generic space glyph (U+0020) similar to that of the letter I or i.

TYPOGRAPHIC RULES

Many languages—including those commonly using the Latin script—have specific typographic rules.

One example: in French, before a question mark, exclamation mark, semi-colon or colon, there is a non-breaking space, whereas there isn’t any in English or other languages.

In digital typesetting, there are variable word spaces, breaking and non-breaking spaces, which give the text processing application the information on whether the width of the space can be adjusted or if the text line can or can not be broken at a specific place.