Underline, also known as underline or underline, is to add a horizontal line similar to proper nouns to words. Underlines are generally divided into single underline, double underline, bold underline, underlined dotted line and so on.

In some documents, underscores are usually used to mark important or obvious words. On the other hand, in web pages, the text that can be connected (hyperlinks) is generally underlined.

Extended data

Underlines were originally used to write or print documents to emphasize words. When a manuscript is typeset, various forms of underlining are often used to indicate that the text should be set to a special font such as italics for emphasis, which is called part of the marking process.

With the emergence of word processing technology, different font styles can be directly used in manuscripts, which makes underline no longer need to exist as a mark, but sometimes it is still used as an emphasis or mark.

For example, in some professional printed matter, people's names are often represented by single underscores and place names by double underscores.

In general text editors such as Word and Gmail, you can usually enter Ctrl+U to underline the text.