Modification of the forms of Drupal

Drupal contains many different forms. Sometimes, not all of them look as you would like. Changing the Drupal forms is a topic that many developers meet with friendly moans of displeasure and misunderstanding. Meanwhile, it is enough to understand only two methods for changing them and everything becomes much clearer and simpler.

Summary:

1. Aspects of change in shape through the theme system
2. Modifying the form in modules
3. Application Forms API
4. Examples for both Drupal branches

Modification of forms in Drupal (carefully, a lot of code).