In the GUI environment, these are rectangular grey buttons that you click with your mouse to make various things happen. In character mode, they appear as differently-colored text enclosed in parenthesis. A push button is simply a shorthand way of triggering some sort of event in the form. This means that the cursor does not navigate to the buttons, and that the only way to use these buttons is with a mouse. When we finally get to GUI, though, you'll love them.
Radio buttons indicate an item which has only one of a limited set of values.
Pressing the space bar will select the item where the cursor is. Remember, that one and only one item in a set of radio buttons can be selected, though there can be more than one set of radio buttons on the screen at a given time. In the GUI environment, these are text fields with a down arrow symbol next to them. The only way to change the value of this item is to select from this list. All of these new Forms items are much more obvious and easy to use in GUI mode.