The document discusses different types of metadata. It defines metadata as "data about data" and provides examples to illustrate this. The key types of metadata discussed are: descriptive metadata, which provides attributes about a resource; administrative metadata, which relates to a resource's creation and management, including technical, provenance, preservation and rights metadata; structural metadata, which provides a resource's organization; and use metadata, which captures how a resource is used. The document emphasizes that metadata is essential for business intelligence tasks like extracting, loading and analyzing data.