A Flex application can consist of MXML files, ActionScript classes, SWF files, and SWC files.
The Flex compiler transforms the main MXML file and its children into a single ActionScript class linking in all the reference-imported classes. Once the transformation is complete, the end result is a single SWF file that can be deployed on the server.
Every time you make changes to your application, a new SWF file is generated. You may find it more convenient to remove the reusable components and compile those into SWC files, which can be included in a library path for your application.
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