En (typography)
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. 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, and increasingly to replace the long dash. This is standard practice in German, another Germanic language, where the hyphen is the only dash without spaces on either side.See standard typographic symbols :
- en space: UTF8
U+2002
and HTML  
. Example: " " - en dash: UTF8
U+2013
and HTML –
. Example: "&endash;"