what is the use of details and summary tag?

Meaning & Implications:

The visible heading of the "details" element is determined by the "summary" tag. The heading can be clicked to see or hide the details. Note: The summary element should be the first child element of the details element.

• Definition and Application:

The "details" element's visible heading is defined by the "summary" tag. To show or conceal the details, click the heading. Note: The summary element ought to be the details element's first child element.