The checked-changed event occurs each time you select or deselect a check box or radio button.
Step-by-step explanation:
CHECK BOX - The check box is used, when the user wishes to make a binary choice. When the check box is selected, the checked property of the check box contains the Boolean value that is either true or false.
RADIO BUTTON - The radio button control is used, when the programmer wishes to limit the user to one choice during input of mutually exclusive options. A total of seven radio buttons can be selected from a group.