A survey allows you to create questions and control the response format.
In a survey, you can create both open-ended and closed-ended questions.
Windows SharePoint Services provides three views in which to summarize survey responses: Overview, Graphical Summary, and All Responses. You can export survey responses to a spreadsheet to perform more complex data analysis.
A discussion board allows users to create and reply to discussion subjects.
You can view discussions in either Subject, Flat, or Threaded view.
You can enable a discussion board to receive incoming e-mail.
You can connect any discussion board to Outlook. These appear under the SharePoint Lists folder.
Surveys and discussion boards are specialized lists. Their permissions can be controlled independently of both the site and of other lists. You can apply item-level permissions to prevent users from editing their survey responses or discussion messages.