The Resource Description Framework (RDF) is a framework for describing Web resources, such as the title, author, modification date, content, and copyright information of a Web page. Before indulging in web development with RDF, you should have sound knowledge of HTML and XML, since RDF is written in XML.
RDF is specifically designed to be read and understood by computers and are is designed to be displayed on the web. By using XML, RDF information can easily be exchanged between different types of computers using different types of operating systems and application languages. The XML language used by RDF is called RDF/XML.
RDF identifies things using Web identifiers (URIs), and describes resources with properties and property values. A Resource is anything that can have a URI, such as http://www.reference.com/rdf. A Property is a Resource that has a name, such as “author” or “homepage”. A Property value is the value of a Property, such as “Black” or “http://www.reference.com.
Consider a detailed example of a RDF document:
rdf:about="http://www.recshop.fake/cd/Hide your heart">
The first line of the RDF document is the XML declaration. The XML declaration is followed by the root element of RDF documents: <rdf:RDF>.
The xmlns:rdf namespace, specifies that elements with the rdf prefix are from the namespace “http://www.w3.org/1999/02/22-rdf-syntax-ns#”.
The xmlns:cd namespace, specifies that elements with the cd prefix are from the namespace “http://www.recshop.fake/cd#”.
The <rdf:Description> element contains the description of the resource identified by the rdf:aboutattribute.
The elements: <cd:artist>, <cd:country>, <cd:company>, etc. are properties of the resource.
In recent years, RDF is being widely used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax formats and hence is considered a very important tool for web developers.