Metadata is "data about data" according to Wikipedia.
Specifically in NetKernel metadata relates to
- Request and Response headers which are used to control ROC abstraction but are also extendable for application use.
- Deployed functionality including endpoint interfaces exposed by the Space Explorer and Endpoint datasheets.
- Captured Request Traces which care used by the Visualizer and contain a snapshot of all execution state whilst processing requests.
- Application level aggregated resources using Space Aggregate HDS.
- Application level aggregated resources using User Meta Aggregator from the <meta> tag.