dropdown

Dropdown refers to a user interface control that presents a list of options hidden by default and revealed when the user activates a trigger. The currently selected item is shown on the trigger, and selecting another item updates the trigger text accordingly. Dropdowns are commonly used for single-choice selection from a compact set of options, such as choosing a country, category, or setting.

Variants and terminology: The term dropdown menu is often used for a list of commands or links. A dropdown list or select element is a standard form control in many environments; a combo box combines a text field with a dropdown list for both free text and selection in some implementations.

Interaction and accessibility: Activation is typically via click or touch, with keyboard support via Enter, Space, and arrow keys to navigate items. The dropdown should close when the user clicks outside or presses Escape. Good practice includes proper focus management, visible label, and ARIA roles such as aria-expanded, role="listbox" for the menu, and role="option" for items.

Design and implementation notes: In web design, native select elements offer basic behavior and accessibility; custom dropdowns provide styling flexibility but require careful scripting to mimic native behavior and to support screen readers. On mobile, touch targets should be large enough, and hover-triggered menus should be avoided in favor of explicit tap activation.