HTML Details Tag
HTML <details> tag is used to specify the additional details on the web page that the user can view or hide on demand.
According to W3C HTML specification, it is used as a disclosure widget from which user can retrieve additional information or control.
It is used together with a relevant tag known as <summary>. Technically, there is no need of summary tag, but if you ignore this then the browser will use some default text.
The <details> tag wraps all the content which you want to show or hide and the <summary> tag contains the summary and the title of the section.
HTML details is a new tag introduced in HTML5.
Let's take an example to understand this clearly.