Linked Data is about using the Web to connect related data that wasn't previously linked, or using the Web to lower the barriers to linking data currently linked using other methods.
It uses Semantic Web technologies to publish structured data on the Web, and set links between data from one data source to data within other data sources. The principle of Linked Data are:
- Use URI s as names for things
- Use HTTP URIs so that people can look up those names
- When someone looks up a URI, provide useful RDF information
- Include RDF statements that link to other URIs so that they can discover related things
Everyone can publish data to the Web of Linked Data. Entities are connected by links, creating a global data graph that spans data sources and enables the discovery of new data sources. Data in the Web of Linked Data is self-describing; if an application encounters data represented using an unfamiliar vocabulary, the application can resolve the URIs that identify vocabulary terms in order to find their RDFS or OWL definitions. The Web of Data is open, so that applicaitons can discover new data sources at runtime by following links.
A problem with the classical Web is that the content is only loosely structured, making it difficult for applications to use the Web and its content in a more complex manner. The solution to this is to increase the structure of the Web content.
The Semantic Web extends the principles of the Web from documents to data; create a Web of data. Data, ontologies , vocabularies, etc. can and should be shared and reused, potentially on Web scale. The major importance of RDF is that it provides an abstract integration layer for data on the Web.