Radio Button
Radio buttons are for making a mutually exclusive decision. Radio buttons are used when there is a list of two or more options that are mutually exclusive and the user must select exactly one choice. In other words, clicking a non-selected radio button will deselect whatever other button was previously selected in the list.
Design Tips
Radio buttons and checkboxes are very similar, except for a few key differences. The primary difference is that with radio buttons you can only select one item, while with checkboxes you can select any number.