These form elements are used to perform certain control functions on a formular. These control functions act in some way on all form elements that are contained in a particular form. Submit and image buttons are used to initiate the submission of a form, while a reset button is used to reset the contents of all form elements to their initial values.
The submit and image button elements are very similar. One difference is
that the label of image buttons is derived the same way as inline images are
replaced by an appropriate text representation, but with the exception that
an empty label is replaced by the text "image" in order to
guarantee that the button element does not disappear. The other difference is
that the dummy coordinates 0,0 are being sent during form
submission instead of the button label as it is being done for submit button
elements. An empty or missing label of submit buttons is replaced by the text
"submit".
During display, the label of a button
element is shown enclosed within a pair of sharp parentheses "<>",
e.g.
<Submit the Form>
Activation of the button element causes the associated function to be performed. Submit and image buttons are also considered to be a kind of hyperlink, so that all actions that act on hyperlinks can also be used together with form submission.