Button

The Button widget in SWT incorporates different types of buttons that can be selected by specifying style flags.

PUSH
Normal push buttons. They have no state. When the buttons is pressed, a selection event is fired.
TOGGLE
Toggle buttons look like push buttons but they maintain a selection state. Once pressed they stay selected until they are pressed again. A selection event is fired on selection and deselection.
CHECK
Check buttons are semantically equivalent to toggle buttons. They also maintain a selection state but this state is displayed as a checkbox.
RADIO
Radio buttons are used to choose between different options. A radio button can only be deselected by selecting another radio button within the same composite.