Semantic Web

The term “Semantic Web” refers to W3C’s vision of the Web of linked data. Semantic Web technologies enable people to create Data stores on the Web, build vocabularies, and write rules for handling data. Linked data are empowered by technologies such as RDF, SPARQL, OWL, and SKOS. According to the W3C, "The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries". The Semantic Web is therefore regarded as an integrator across different content, information applications, and systems.

The term was coined by Tim Berners-Lee for a web of data (or data web) that can be processed by machines. Berners-Lee originally expressed his vision of the Semantic Web as follows:

I have a dream for the Web [in which computers] become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers. A "Semantic Web", which makes this possible, has yet to emerge, but when it does, the day-to-day mechanisms of trade, bureaucracy, and our daily lives will be handled by machines talking to machines. The "intelligent agents" people have touted for ages will finally materialize.

Standards behind the Semantic Web
Many of the Semantic Web standards were drafted in 2001, but they have now been formalized and ratified. Though they are many technologies and standards that exist in this space, we have seen three that have stood out:

1. RDF (Resource Description Framework): The data modeling language for the Semantic Web. All Semantic Web information is stored and represented in the RDF. It provides machine-understandable semantics for metadata.

2. SPARQL (SPARQL Protocol and RDF Query Language): The definitive query language of the Semantic Web.

3. OWL (Web Ontology Language): The schema language, or knowledge representation (KR) language, of the Semantic Web.

Web 3.0
"Semantic Web" is sometimes used as a synonym for "Web 3.0", though the definition of each term varies. Web 3.0 has started to emerge as a movement away from the centralization of services like search, social media and chat applications that are dependent on a single organization to function.