The clippings are organized and saved to disk and you are given the opportunity to add your own comments and annotations. Scrapbook also stores the origianl URL of the clipping so you can visit the full text of the site in the future, if needed.
You can capture Web page by following 3 ways.
* On the Web page, right-click > [Capture Web Page]
* Select a snippet of Web page, right-click > [Capture Selection]
* Select a snippet of Web page, drag-and-drop it on the ScrapBook Sidebar
Get more information here - ScrapBook :: Mozilla Firefox Extension