summary

I. Description

The 'summary' element holds the text which is always visible to the user inside of a 'details' element. The 'summary' element is always a child of a 'details' element. The text which gets displayed to the user when the user clicks on the 'summary' element is the text which is inside of the 'details' element but NOT inside of the 'summary' element.

II. Examples

<!DOCTYPE html>
<html>
    <head>
        <title>Example Page</title>
    </head>
    <body>
        <h1>Summary Example</h1>
        <details>
            <summary>HTML (Hypertext Markup Language)</summary>
            HTML is a markup language designed to encode or 'markup' information
            which may be viewed using a web browser such as Google Chrome or Safari.
        </details>
    </body>
</html>