A lot of things that you normally see in Outlook are forms. When you compose a new message you fill out the Message form. When you create a new contact you do it by invoking the Contact form. Some of the forms such as the Message form are one page dialogs. Others such as the Contact form have multiple pages.
Outlook comes with a few predesigned forms.
You may explore their possibilities by navigating to File - New menu list. Conceptually, each form is designed for a well defined purpose. The Message form creates an outgoing message, the Note creates a memo note and so on. You can modify an existing form or design your own by removing all controls from an existing one and starting all over from scratch. You can add controls such as buttons to a form and even associate Visual Basic scripts with them.