A dropdown menu is a graphical user interface element that allows users to select an option from a list that appears when they click on a button or text. This feature is commonly used in websites and applications to save space and organize options neatly. When the user clicks the menu, it "drops down" to reveal the available choices. Dropdown menus can contain various items, such as links to different pages, settings, or categories. They enhance user experience by providing a simple way to navigate through options without overwhelming the interface. Commonly seen in web design, they are essential for creating intuitive user interfaces.