This is how it differs from the Text Box Control. The Pointer isn't really a tool. It is the default for navagation when there are no tools selected. The Radio Button is like the Check Box, in that it allows for the user to select certain options. The Radio Button, however, is usually used when ther is only one selection to be taken out of several possibilities.
Shapes can have code just like any other control.
The Text Box Control allows for the user to input data that can be used by the program. This data can be manipulated or sent to a file, etc.