MACROMEDIA STUDIO 8-EXPLORING STUDIO 8 Manual page 58

58 Studio Basics
ActionScript code is the programming code you can add to Flash
documents to make them respond to user interactions and to more finely
control the behavior of your Flash documents. Much can be accomplished
in Flash without ActionScript, but using ActionScript offers many
more possibilities.
Flash can be used to work with a variety of file types. Each type has a
separate purpose. The following list describes each file type and its uses:
FLA files are the primary files you work with in Flash. These are the
files that contain the basic media, Timeline, and script information for
a Flash document.
SWF files are the compressed versions of FLA files. These files are the
ones you display in a web page.
AS files are ActionScript files. You can use these files if you prefer to
keep some or all of your ActionScript code outside of your FLA files.
These can be helpful for code organization and for projects that have
multiple people working on different parts of the Flash content.
SWC files contain the reusable Flash components. Each SWC file
contains a compiled movie clip, ActionScript code, and any other assets
that the component requires.
ASC files are files used to store ActionScript that will be executed on a
computer running Flash Communication Server. These files provide
the ability to implement server-side logic that works in conjunction
with ActionScript in a SWF file.
JSFL files are JavaScript files that you can use to add new functionality
to the Flash authoring tool. See Extending Flash for more information.
FLP files are Flash Project files (Flash Professional 8 only). You can use
Flash Projects to manage multiple document files in a single project.
Flash Projects allow you to group multiple, related files together to
create complex applications.