Explain use of global elements, namespaces, and xml metadata models (xhtml, docbook, resource description framework (rdf), and really simple syndication (rss).

Global elements are elements that are children of a schema element

They are root elements and used to tag or label the programming schema or structure.

Global Elements must be declared before it's used.

Namespace:

Codes must be grouped or organised into logical groups. This can be achieved using namespaces because it so prevent name collision especially when there are lots of libraries in the code.

XHTML(eXtensible HyperText Markup Language) is used ease site accessibilities and also used to structure a site using well structured codes.

DocBook

DocBook which was initially meant for writing and accessing technical documents in XML and dbk extensions , is a semantic markup language for technical documentation.

Resource Description Framework (RDF)

RDF which was initially designed for metadata data model, is a member of www that is used for conceptual description or modeling of information that is implemented in web resources.

Really Simple Syndication (RSS).

RSS is a type of web syndicate that is lets the users of a website have access to updates on the website in a standardised and computer readable format.

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