The URLLoader class downloads data from a URL as text, binary data, or URL-encoded variables. It is useful for downloading text files, XML, or other information to be used in a dynamic, data-driven application. A URLLoader object downloads all of the data from a URL before making it available to ActionScript. It sends out notifications about the progress of the download, which you can monitor through the bytesLoaded and bytesTotal properties, as well as through dispatched events.

The Loader class is used to load SWF files or image (JPG, PNG, or GIF) files. Use the load() method to initiate loading. The loaded display object is added as a child of the Loader object.