Radio Button
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.
Access
Radio buttons support sequential element navigation. This means that you can move the focus forwards to a radio button using Tab or backwards to a radio button using Shift + Tab. If you access a radio button group, the radio button you have currently selected is highlighted.
Internal Navigation
Use the arrow keys to move the focus between 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.
Help Functions
If the radio button has a tool tip, you can call it up by choosing Ctrl + q.