The Collapsible panel web part displays a panel that can be collapsed or expanded by users. The panel contains a web part zone, so any type of content may be added into it.
More information about layout web parts in Kentico CMS can be found in Kentico CMS Developer's Guide -> Development -> Web parts -> Layout web parts.
Collapsible panel details
This layout provides the header and panel that can be collapsed or extended based on the settings. See the web part properties for details.