What Is Metadata?

If you’ve been building applications using the Flex framework, you are probably already familiar with metadata tags, but what are they exactly? In the loosest terms, metadata is data that describes other data, generally through descriptive labels. So, what does that actually mean in relation to developing components?

Metadata within the Flex framework (and specifically, component development) can be divided in to three distinct groups: those that integrate with Flash Builder, those that act as compilation markers, and those that provide validation. Of these three groups, the majority of metadata tags fall into the initial group: those that integrate with Flash Builder. Now, if you already looked at this book’s Table of Contents, you probably noticed that there’s an entire chapter on integrating your components with Flash Builder, so why didn’t I just put this information in there and remove this chapter?