U+23AF Horizontal Line Extension

The Wikipedia has the following information about this codepoint:

The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the baseline. The most common versions are the en dash –, generally longer than the hyphen but shorter than the minus sign; the em dash —, longer than either the en dash or the minus sign; and the horizontal bar ―, whose length varies across typefaces but tends to be between those of the en and em dashes.

Typical uses of dashes are to mark a break in a sentence, or to set off an explanatory remark (similar to parenthesis), or to show spans of time or ranges of values.

The em dash is sometimes used as a leading character to identify the source of a quoted text.