Difference between Metadata and Annotations

Question: What is the distinction between metadata and annotations? Aren't annotations just another form of metadata?

Response: We understand there is a lot of overlap between information stored as metadata and information stored as annotations. The distinction we make is that metadata is coming primarily from catalogers and annotations are coming primarily from users. Another distinction is that metadata is generally a fully defined description, while annotations are small extensions that may not be as meaningful without the context of fully defined metadata. Additionally metadata describes a resource directly, while annotations tend to describe an extension to metadata, although this is not always the case.