Overlays & Surfaces · Containers
Collapsible
also known as collapse, collapsible panel
A collapsible is a container whose content can be folded away and reopened, saving space and letting users focus on what they need. It's the same core behavior as a disclosure or expander, and the name Bootstrap and many libraries use for a single toggling region. When multiple collapsibles are grouped, they form an accordion.
See it live — shadcn/ui · MUI · Ant Design
Don't confuse it with
Collapsible, disclosure, and expander are interchangeable names for a single show/hide region. Group several together with coordinated behavior and you get an accordion.
In the wild
Bootstrap's Collapse component that toggles a hidden panel open and closed is a collapsible.