# linked data

> structured data and method for its publication

**Wikidata**: [Q515701](https://www.wikidata.org/wiki/Q515701)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Linked_data)  
**Source**: https://4ort.xyz/entity/linked-data

## Summary
Linked data is structured data and its method of publication, enabling the interconnection of datasets across the web through standardized formats and unique identifiers. It forms a core component of the Semantic Web, allowing machines to understand and process data meaningfully by using technologies like RDF, ontologies, and URIs.

## Key Facts
- A structured data publication method that enables interconnection of datasets across the web
- Forms a core component of the Semantic Web, which extends the World Wide Web to facilitate data exchange
- Uses Resource Description Framework (RDF) as a data model for describing web resources
- Relies on Uniform Resource Identifiers (URIs) to uniquely identify resources on networks
- Built upon technologies including ontologies for specifying conceptualizations and XML for encoding structured data
- Connected to the World Wide Web as its parent system
- Related to semantic networks as directed graph structures with labeled edges
- Associated with academic disciplines and fields of study
- Connected to the Resource Description Framework (RDF) as a data model for describing web resources
- Uses SPARQL as an RDF query language developed by the World Wide Web Consortium
- Connected to various individuals including Tim Berners-Lee, Rudi Studer, Nigel Shadbolt, Markus Krötzsch, Wendy Hall, Carole Goble, and Katia Sycara
- Related to semantic integration as a process of interrelating information from diverse sources
- Connected to projects like Wikidata, DBpedia, and various authority files
- Uses ontologies as specifications of conceptualizations
- Connected to the Virtual International Authority File, Library of Congress Control Number, and BnF authorities
- Related to EuroVoc as the EU's multilingual thesaurus
- Connected to Project Gutenberg as a volunteer effort to digitize and archive books
- Uses NGSI-LD as a standard
- Connected to various newspapers and information systems
- Part of structured data, online database, and linked open data
- Contains the Semantic Web as an extension of the Web to facilitate data exchange
- Designed by the World Wide Web Consortium, an international standards organization for the World Wide Web
- Used by academic disciplines, fields of study, and the Solid web decentralization project

## FAQs
### Q: What is linked data and how does it differ from traditional data?
A: Linked data is a structured data publication method that enables the interconnection of datasets across the web using standardized formats and unique identifiers. Unlike traditional data, which is often siloed and incompatible, linked data allows for seamless integration and querying across different systems through technologies like RDF and URIs.

### Q: What technologies form the foundation of linked data?
A: Linked data is built on technologies including the Resource Description Framework (RDF) for describing web resources, ontologies for specifying conceptualizations, and Uniform Resource Identifiers (URIs) for uniquely identifying resources. It also relies on XML for encoding structured data and follows principles for publishing and connecting structured data on the web.

### Q: Who are the key figures in the development of linked data?
A: Key figures in the development of linked data include Tim Berners-Lee, who invented the World Wide Web and created fundamental protocols, along with researchers like Rudi Studer, Nigel Shadbolt, Markus Krötzsch, Wendy Hall, Carole Goble, and Katia Sycara who have made significant contributions to semantic technologies and knowledge representation.

### Q: How does linked data relate to the Semantic Web?
A: Linked data is a structured data publication method that forms a core component of the Semantic Web. The Semantic Web extends the World Wide Web to facilitate data exchange by using structured data formats and metadata to make information more meaningful to computers, enabling machines to understand and process web content through technologies like ontologies and formal knowledge representation.

### Q: What role do ontologies play in linked data?
A: Ontologies serve as specifications of conceptualizations in linked data, providing formal descriptions of concepts, properties, and relationships within a particular domain. They enable machines to understand the meaning of data and facilitate automated reasoning and inference across different knowledge bases, which is crucial for the interoperability and integration of datasets in linked data systems.

## Why It Matters
Linked data addresses the fundamental challenge of making web content understandable to machines, not just humans. Traditional web pages are formatted for human consumption, making it difficult for computers to extract meaning and relationships from the data. Linked data solves this by using structured data formats and metadata to describe content and its relationships, enabling automated processing and integration of information across different systems.

This technology has revolutionized how data is structured and exchanged across different systems and platforms. Before linked data, data formats were often proprietary and incompatible, making it difficult to share information between different software applications. Linked data provides standardized ways to represent data that are both human-readable and machine-processable, enabling interoperability between different systems and platforms.

The impact extends to numerous domains including bioinformatics, library science, government data, and enterprise information management. Projects like DBpedia extract structured data from Wikipedia, while initiatives like Wikidata provide multilingual knowledge graphs. The technology enables sophisticated querying and reasoning capabilities through languages like SPARQL, allowing for complex data integration and analysis that would be impossible with traditional web technologies.

Linked data has also enabled the creation of knowledge graphs used by major technology companies and has influenced how governments publish open data. It provides the foundation for artificial intelligence applications that require structured knowledge about the world, supporting everything from search engines to recommendation systems to automated decision-making tools.

## Notable For
- A structured data publication method that enables interconnection of datasets across the web
- Foundation for linked data principles that connect datasets across the web
- Use of ontologies to provide formal specifications of conceptualizations
- Support for automated reasoning and inference through technologies like RDF and OWL
- Connection to the Resource Description Framework as a foundational data model
- Development of SPARQL as a powerful query language for RDF data
- Influence on major web standards and protocols through the World Wide Web Consortium
- Application in diverse fields from bioinformatics to library science to government data
- Creation of large-scale knowledge bases like DBpedia and Wikidata
- Enablement of cross-domain data integration through standardized formats
- Provision of formal semantics that allow machines to understand data meaning

## Body
### History and Development
Linked data emerged as a structured data publication method to enable the interconnection of datasets across the web. It builds upon foundational technologies developed by the World Wide Web Consortium, including XML, which was introduced as a W3C Recommendation in 1998. The development was led by key figures in computer science who recognized the need for more structured approaches to web data.

The concept builds on earlier work in knowledge representation and artificial intelligence, connecting to semantic networks as directed graph structures with labeled edges serving to encode and represent knowledge. This approach allows for the encoding of both definitions and assertions in a machine-processable format.

### Core Technologies and Architecture
Linked data relies on several core technologies that work together to enable machine understanding of web content. At its foundation is the Resource Description Framework (RDF), which serves as a data model for describing resources on the Web. RDF provides a standardized way to represent information about web resources and their relationships.

Ontologies play a crucial role as specifications of conceptualizations, defining the terms and relationships used to describe and represent a particular domain. These ontologies provide the vocabulary and logical structure necessary for machines to understand the meaning of data.

Uniform Resource Identifiers (URIs) are used extensively to identify resources on networks, providing globally unique identifiers that enable linking and referencing across the web. This creates a web of interconnected data that can be traversed and understood by machines.

### Linked Data and Data Integration
Linked data represents a structured approach to data publication that is central to the Semantic Web. This method enables the publication of structured data in a way that allows different datasets to be interconnected and queried across the web. The approach follows specific principles for publishing and connecting structured data on the web.

The Semantic Web facilitates semantic integration, which involves interrelating information from diverse sources. This process allows for the combination of data from different systems, formats, and domains, creating unified views of information that would otherwise remain siloed.

### Querying and Reasoning Capabilities
SPARQL serves as the RDF query language, providing powerful capabilities for querying Semantic Web data. Developed by the World Wide Web Consortium, SPARQL enables complex queries across distributed datasets and supports various operations including pattern matching, aggregation, and federation.

The Semantic Web supports automated reasoning through various logical frameworks, allowing systems to infer new knowledge from existing data. This capability enables sophisticated applications that can draw conclusions and make recommendations based on the structured knowledge encoded in semantic web formats.

### Applications and Ecosystem
Linked data has found applications across numerous domains, from bioinformatics and life sciences to cultural heritage and government data. Projects like DBpedia extract structured data from Wikipedia, creating large-scale knowledge bases that can be queried and integrated with other datasets.

Wikidata represents a free multilingual online knowledge graph that demonstrates the power of collaborative semantic web technologies. Various authority files including the Virtual International Authority File, Library of Congress Control Number, and BnF authorities utilize semantic web technologies to create interconnected identity management systems.

### Key Contributors and Research
The development of linked data has involved numerous researchers and practitioners. Tim Berners-Lee, inventor of the World Wide Web, has been instrumental in advancing semantic web technologies through his work at the World Wide Web Consortium. Rudi Studer has contributed significantly through his academic leadership and research in knowledge-based systems at the Karlsruhe Institute of Technology.

Nigel Shadbolt has advanced the field through his work in artificial intelligence and informatics, particularly through his role as Chairman of the Open Data Institute. Markus Krötzsch has made significant contributions to semantic technologies, including the development of Semantic MediaWiki and research in ontology-based data management.

Wendy Hall has been a pioneer in the development of the Semantic Web and co-founded the World Wide Web Consortium. Carole Goble has applied Semantic Web technologies to bioinformatics and life sciences through her work on the ELIXIR project.

### Standards and Organizations
The World Wide Web Consortium plays a central role in developing standards for linked data, ensuring interoperability and continued evolution of the technology. The consortium has developed numerous specifications including RDF, OWL (Web Ontology Language), and SPARQL.

Various organizations and projects contribute to the semantic web ecosystem, including EuroVoc as the EU's multilingual thesaurus and Project Gutenberg as a volunteer effort to digitize and archive books using semantic principles. These initiatives demonstrate the broad applicability of semantic web technologies across different domains and use cases.

### Related Entities
Linked data is part of structured data, online database, and linked open data. It contains the Semantic Web as an extension of the Web to facilitate data exchange. It is designed by the World Wide Web Consortium, an international standards organization for the World Wide Web, and used by academic disciplines, fields of study, and the Solid web decentralization project.

## References

1. Freebase Data Dumps. 2013
2. [Registros de autoridad de "Materia" de la Biblioteca Nacional de España. Spain open data portal](https://www.bne.es/media/datosgob/catalogo-autoridades/materia/materia-UTF8.zip)
3. [Source](https://wordlift.io/blog/en/entity/linked-data/)
4. National Library of Israel
5. Wikibase TDKIV