From the W3C:
The Semantic Web is a Web of Data — of dates and titles and part numbers and chemical properties and any other data one might conceive of. The collection of Semantic Web technologies (RDF, OWL, SKOS, SPARQL, etc.) provides an environment where application can query that data, draw inferences using vocabularies, etc.
However, to make the Web of Data a reality, it is important to have the huge amount of data on the Web available in a standard format, reachable and manageable by Semantic Web tools. Furthermore, not only does the Semantic Web need access to data, but relationships among data should be made available, too, to create a Web of Data (as opposed to a sheer collection of datasets).
This collection of interrelated datasets on the Web can also be referred to as Linked Data.
For more information see: https://www.w3.org/standards/semanticweb/data
The Resource Description Framework (RDF) is a family of World Wide Web Consortium (W3C) specifications originally designed as a metadata data model. It has come to be used as a general method for conceptual description or modeling of information that is implemented in web resources, using a variety of syntax notations and data serialization formats. It is also used in knowledge management applications. RDF was adopted as a W3C recommendation in 1999. The RDF 1.0 specification was published in 2004, the RDF 1.1 specification in 2014.
Also see RDFa and RDF query language.
The Semantic Web is a collaborative movement led by the international standards body, the World Wide Web Consortium (W3C). The standard promotes common data formats on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web dominated by unstructured and semi-structured documents into a “web of data”. The Semantic Web stack builds on the W3C’s Resource Description Framework (RDF).
Also see linked data and knowledge graphs.
This Scientific American feature article from May 2001 sets out the vision (and yes, this is also a fun example of what a staid web page looked like in 2001):
The Semantic Web
A new form of Web content that is meaningful to computers will unleash a revolution of new possibilities
by Tim Berners-Lee, James Handler and Ora Lasilla
Also see:
Introduction to Semantic Technology
and for a slightly more skeptical point of view:
Web 2.0, 3.0 and so on
and this:
Why Adding Semantics to Web Data is Difficult
In computer science and information science, an ontology is a formal naming and definition of the types, properties, and interrelationships of the entities that really or fundamentally exist for a particular domain of discourse. It is thus a practical application of philosophical ontology, with a taxonomy. An ontology compartmentalizes the variables needed for some set of computations and establishes the relationships between them. The fields of artificial intelligence, the Semantic Web, systems engineering, software engineering, biomedical informatics, library science, enterprise bookmarking, and information architecture all create ontologies to limit complexity and to organize information. The ontology can then be applied to problem solving.
Our coverage of semantic technologies goes back to the early 90s when search engines focused on searching structured data in databases were looking to provide support for searching unstructured or semi-structured data. This early Gilbane Report, Document Query Languages – Why is it so Hard to Ask a Simple Question?, analyses the challenge back then.
Semantic technology is a broad topic that includes all natural language processing, as well as the semantic web, linked data processing, and knowledge graphs.
Natural language processing (NLP) is a subfield of linguistics, computer science, information engineering, and machine learning or artificial intelligence concerned with the interactions between computers and human (natural) languages, in particular how to program computers to process and analyze large amounts of natural language data.
Categorization is the process in which ideas and objects are recognized, differentiated, and understood. Categorization implies that objects are grouped into categories, usually for some specific purpose. Ideally, a category illuminates a relationship between the subjects and objects of knowledge. Categorization is fundamental in language, prediction, inference, decision making and in all kinds of environmental interaction.
A web style sheet is a form of separation of presentation and content for web design in which the markup of a webpage contains the page’s semantic content and structure, but does not define its visual layout (style). Instead, the style is defined in an external style sheet file using a style sheet language such as CSS or XSLT. This design approach is identified as a “separation” because it largely supersedes the antecedent methodology in which a page’s markup defined both style and structure.
Also see XSL-FO.
Style sheets predate web publishing and were used in proprietary electronic publishing publishing systems in the early 80s.
