A series of on-screen buttons that allow only one selection to be made from the group. If a button is currently selected, it will de-select when any other button is selected. Radio buttons come from the early days of radio, which had five or six preset station buttons in a row. Pressing one button deselected the other station.
This type of selection is used whenever there is only one choice out of several. Choosing one deselects the others. Pressing a preset station button on old radios pushes out the others.