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CDAP metadata, consisting of properties (a list of key-value pairs) or tags (a list of keys), can be used to annotate artifacts, applications, programs, datasets, streams, views, and custom entities.
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CDAP Metadata UI: Lets you see how data is flowing into and out of datasets, streams, and stream views.
Accessing metadata programmatically: Metadata can be retrieved or updated programmatically from CDAP programs and plugins, primarily for enabling metadata based processing.