The dash is a punctuation mark that is similar to a hyphen or minus sign, but differs from both of these symbols primarily in length and function. The most common versions of the dash are the en dash (–) and the em dash (—), whose names historically were loosely associated with the length of a lower-case n and upper-case M, respectively, in commonly used typefaces. Usage varies both within English and in other languages, but the usual convention in printed English text is as follows: