An Accordion is a set of collapsible panels that can store a large amount of content
in a compact space. Site visitors hide or reveal the content stored in the accordion
by clicking the tab of the panel. The panels of the accordion expand or contract
accordingly as the visitor clicks different tabs. In an accordion, only one content
panel is open and visible at a given time.
It is a very useful control that allows you to provide multiple panels but show
them one at a time with a smooth, gliding effect.