Creating a simple jump menu module from taxonomy terms using the Form API
If you come from a background where you have created your own forms directly in HTML, you may find Drupal’s approach a bit confusing at first. Drupal presents an application programming interface (API) for generating, validating, and processing HTML forms. The form API abstracts forms into a nested array of keys (referred to as properties) and values. Rather than output HTML, we create an array and let the engine generate the HTML.