Radio buttons are a type of input element that allows users to select only one option from a list of mutually exclusive options. They are commonly used in forms where users need to select one option from a set of options. 

A radio button should always have a clear and concise label next to it, so users can quickly understand what each option represents. The labels should also be phrased consistently, so users can easily compare and contrast the options.

(also see `Radio group` component)