RadioButton control looks by default like on the picture below. Its purpose is to allow user to select one option from a group. This control is designed to be used in group. It mean, you will usually create several of them with same GroupIndex property. User will be able to activate only one of them. When he activates another RadioButton all the rest from the group will be automatically deactivated. You may assign different group indexes to have independent sets of options.

RadioButton control(widget)