SharePoint Designer Editing
Using the Microsoft Office SharePoint Designer 2007 client-side Web site editing tool to access and modify content in a SharePoint site. This policy does not include using Office SharePoint Designer 2007 to modify any of the files stored on the file system, which is strictly prohibited, as are any file system-level customizations.
Real World Example
A Web designer needs to make some customizations to an existing SharePoint site's user interface, and add some no-code workflows to the SharePoint site. She uses Office SharePoint Designer 2007 to access and modify items in the site, including master pages, content pages, workflows, and Web Parts on the pages.
Office SharePoint Designer 2007 is the preferred application for making more advanced content changes on SharePoint sites.
Some Office SharePoint Designer 2007 modifications can cause a site to work improperly. In some cases, you can rectify this by using the site collection recycle bin to restore the affected content to its previous working state. Other cases can require deeper levels of support, such as copying a previous version of a file or list from a backed-up version, which can add significant cost to the support request.