Forms are used for content entry. Forms contain tabs that in turn contain fields. Form content is submitted by executing a form action. You can define a form in a dialog and in the editor component of a detail subapp.
Here is a form in the detail subapp of the Contacts app .
Here's the rendered form.
<action name>: Reference to an action definition that submits the form. The value is the name of the action definition node.
<tab name>: See Tab definition.
description: Help text displayed when the user clicks the info button. Optional.
i18nBasename: Message bundle for localized labels. The bundle can be defined at dialog, form, tab or field level. Optional.
label: Field label displayed to editors. The value can be literal such as
Product nameor retrieved from the message bundle with a key such as
products.product.label. Use alphanumeric characters in literal values.
name: Name of the form. Optional.