InfoPath 2007 enables the quick and easy creating of user forms.
One thing that has bugged my is the "form" word.
In english language, "form" means the aspx pages created to insert content, but also mean the "parts" that are added to the page that contain the New/Update/Insert form.
So, to create those insertion forms, infopath is really cool cause it creates filled out out-of-the-box templates and may create document libraries or site collumns and content types all together.
To use infopath, you can let it use/create a document library or you can create a "form library".
Note: as discussion boards, the form libraries will only be available for selection once "Team Collaboration Lists" feature is active on site features.