17.1 Introduction to forms An HTML form is a section of a document containing normal content, markup, special elements called controls (checkboxes, radio buttons, menus, etc.), and labels on those controls. Users generally "complete" a form by modifying its controls (entering text, selecting menu items, etc.), before submitting the form to an agent for processing (e.g., to a Web server, to a mail
![Forms in HTML documents](https://cdn-ak-scissors.b.st-hatena.com/image/square/1d987356f4554089f65b9ed30ba0063d943f2c05/height=288;version=1;width=512/https%3A%2F%2Fwww.w3.org%2FTR%2Fhtml401%2Fimages%2Fform_exmpl.gif)