An en is a typographic unit, half of the width of an em. By definition, it is equivalent to half of the height of the font (e.g. in 16 point type it is 8 points). As its name suggests, it is also traditionally the width of an uppercase letter "N".
The en dash (–) and en space ( ) are each one en wide. In English, the en dash is commonly used for inclusive ranges (e.g., "pages 12–17" or "August 7, 1988 – November 26, 2005"), and increasingly to replace the long dash ("—", also called an em dash or en rule). (When using it to replace a long dash, spaces are needed either side of it – like so.) This is standard practice in German, another Germanic language, where the hyphen is the only dash without spaces on either side. (And line breaks are not spaces per se.)
ensp and ndash. Encodings:
- en space: U+2002 EN SPACE (HTML
- en dash: U+2013 – EN DASH (HTML
See also standard typographic symbols