A radio button is a user interface element you can use to choose a single item from a list of items. A radio button consists of a round element and a descriptive text.
Like a checkbox, a radio button can be selected or deselected. However, single radio buttons are not implemented, since radio buttons are only used to select one item exclusively from a list of items.
Radio buttons support sequential element navigation. You use them to move the focus forwards to a radio button group using [Tab] or backwards using [Shift]+[Tab]. If you access a radio button group, the radio button you have currently selected is highlighted.
Use the arrow keys to move the focusbetween the different radio buttons within a radio button group. The focused radio button item is selected automatically.
When you use the arrow keys in conjunction with the [Ctrl] key, you can move the focus independently of the selection. When you reach the radio button item you require, you can use the [Space] key to select the focused radio button.
If the radio button has a tool tip, you can call it up by choosing [Ctrl]+[q].