A quick definition of dynamic content could be this: to always have current information or to update regularly. For a better explanation of the importance of dynamic content, here are some of my own experiences with static and dynamic content.
When I first started building applications in Flash, way back in Flash 4, I used to create the interface, all the buttons, text fields, and movie clips right on the stage. All the content would also either be on the stage with the other elements or held in ActionScript waiting to be called.
As clients began to request changes (and they always do), I would have to go into the Flash document (because none of them would have Flash to be able to open the source file), find where the content was, and change it, hoping that I would not have to make another change, which of course I would.
After doing this several times, I decided to start keeping major content in external .txt files or in databases (which is discussed in later chapters). That way, whenever I needed to change content, all I would have to do is change a text file or a database entry. The clients could make changes to text files because they would need only a text editor, and then the application or website would reflect those changes. This way, if I had to make changes, I could do them quickly and would not have to upload the entire application again. Even better, the clients had much more control over their own site (which may or may not be a good thing).
So, as you can see, dynamic content is invaluable in building quality, content-driven sites or applications.
To get started with dynamic content, we will cover the getURL() method, the simplest way to send data out of the Flash environment.