A radio button is a close cousin to a checkbox. Unlike the checkbox though, it is meant for many radio buttons to be grouped together so that only one radio button in a group may be selected at a time. It is commonly used when there are a small, fixed number of choices that require different text for each one such that a ChoiceField might not be the best way to present the information to the user.
The RadioButtonField uses a small circle, or dimple, instead of a square like the CheckboxField. They do follow the industry standards, meaning they are arranged the same way as a checkbox by putting the radios on the left-hand side of the screen and the labels on the right.
RadioButtonField cannot be used without a RadioButtonGroup to go along with it. Using just one radio button doesn't make sense—that would essentially be a broken checkbox—and attempting to do so causes your application to crash; so don't do it. The RadioButtonGroup does the real work when it comes to making the...