<vaadin-accordion> is a Web Component providing accordion functionality, part of the Vaadin components.
<vaadin-accordion>
<vaadin-accordion-panel theme="filled">
<div slot="summary">Accordion Panel 1</div>
<div>Accordion is a set of expandable sections.</div>
</vaadin-accordion-panel>
<vaadin-accordion-panel theme="filled">
<div slot="summary">Accordion Panel 2</div>
<div>Only one accordion panel can be opened.</div>
</vaadin-accordion-panel>
</vaadin-accordion>