A Check box is a user selectable button. These are commonly used for multi-choice questions where multiple answers can be selected. Here is an example of a grouped set of checkboxes:
Instructions
Click Add Checkbox .
A new item will appear in the form labelled "New checkbox".
Click the Edit button to the right of the new item .
Change the "New checkbox" [Label] to your required text. This will be used to label the button, for example "Guinea Pig".
[Belongs to Set] governs what other checkboxes this button is associated with. For our example we would add the button "Guinea Pig" to the set "Current Pets".