Every time I talk with someone about metadata, I have the feeling we are talking past each other, at least a little. We are both using the same word, “metadata”, but it often seems like we mean different thing by it. So, what does “metadata” mean?
Metadata is simply data about data, or, to put it another way, data that describes other data. Metadata is ubiquitous. Indeed most data is useless without metadata to tell us what it means. And because metadata is also data, we need metadata to tell us what the metadata means.