JSON-LD (JavaScript Object Notation for Linked Data) is a method of encoding

linked data In computing, linked data (often capitalized as Linked Data) is structured data which is interlinked with other data so it becomes more useful through semantic queries. It builds upon standard Web technologies such as HTTP, RDF and URIs, but ...

using

JSON JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other se ...

. One goal for JSON-LD was to require as little effort as possible from developers to transform their existing JSON to JSON-LD. JSON-LD allows data to be serialized in a way that is similar to traditional JSON. It was initially developed by the JSON for Linking Data Community Group before being transferred to the RDF Working Group for review, improvement, and standardization, and is currently maintained by the JSON-LD Working Group. JSON-LD is a World Wide Web Consortium Recommendation.

Design

JSON-LD is designed around the concept of a "context" to provide additional mappings from JSON to an RDF model. The context links object properties in a JSON document to concepts in an

ontology In metaphysics, ontology is the philosophy, philosophical study of being, as well as related concepts such as existence, Becoming (philosophy), becoming, and reality. Ontology addresses questions like how entities are grouped into Category ...

. In order to map the JSON-LD syntax to RDF, JSON-LD allows values to be coerced to a specified type or to be tagged with a language. A context can be embedded directly in a JSON-LD document or put into a separate file and referenced from different documents (from traditional JSON documents via an

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide We ...

Link header).

Example

The example above describes a person, based on the FOAF (friend of a friend) ontology. First, the two JSON properties name and homepage and the type Person are mapped to concepts in the FOAF vocabulary and the value of the homepage property is specified to be of the type @id. In other words, the homepage id is specified to be an IRI in the context definition. Based on the RDF model, this allows the person described in the document to be unambiguously identified by an IRI. The use of resolvable IRIs allows RDF documents containing more information to be transcluded which enables clients to discover new data by simply following those links; this principle is known as Follow Your Nose. By having all data semantically annotated as in the example, an RDF processor can identify that the document contains information about a person (@type) and if the processor understands the FOAF vocabulary it can determine which properties specify the person’s name and homepage.

Use

The encoding is used by Schema.org, Google Knowledge Graph, and used mostly for

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activities. It has also been used for applications such as

biomedical informatics Health informatics is the field of science and engineering that aims at developing methods and technologies for the acquisition, processing, and study of patient data, which can come from different sources and modalities, such as electronic hea ...

, and representing

provenance Provenance (from the French ''provenir'', 'to come from/forth') is the chronology of the ownership, custody or location of a historical object. The term was originally mostly used in relation to works of art but is now used in similar senses i ...

information. It is also the basis of Activity Streams, a format for "the exchange of information about potential and completed activities", and is used in ActivityPub, the federated social networking protocol. Additionally, it is used in the context of

Internet of Things (IoT) The Internet of things (IoT) describes physical objects (or groups of such objects) with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other comm ...

, where a Thing Description, which is a JSON-LD document, describes the network facing interfaces of IoT devices.

References

External links

JSON-LD.org
{{W3C standards Resource Description Framework Data serialization formats Markup languages JSON Semantic Web

Design

Example

Use

See also

References

External links