How is metadata best defined?

Metadata is best defined as "data about data." It provides essential information that helps describe the characteristics of the primary data, such as its format, structure, quality, source, and context. This descriptive layer of information allows users to understand what the data represents, how it was collected, and how it should be interpreted.

For example, in a dataset containing customer information, the metadata might include field names, data types, and descriptions of each attribute. This helps users efficiently navigate and utilize the dataset without needing to access the raw data itself continuously.

Other options do not accurately capture the essence of metadata. While the size of a dataset can be considered a numerical attribute, it does not encompass the comprehensive informational nature of metadata. Likewise, a type of data visualization is unrelated, as visualization conveys data insights rather than describing the data itself. Finally, a form of data storage pertains to how data is saved rather than the descriptive context that metadata provides about that stored data.