Terms imported from Other Specifications

Terms imported from [[[ECMASCRIPT]]] [[ECMASCRIPT]], [[[RFC8259]]] [[RFC8259]], [[[INFRA]]] [[INFRA]], and [[[WEBIDL]]] [[WEBIDL]]

array

In the JSON serialization, an array structure is represented as square brackets surrounding zero or more values. Values are separated by commas. In the internal representation, a list (also called an array) is an ordered collection of zero or more values. While JSON-LD uses the same array representation as JSON, the collection is unordered by default. While order is preserved in regular JSON arrays, it is not in regular JSON-LD arrays unless specifically defined (see the Sets and Lists section of JSON-LD 1.1.

boolean

The values true and false that are used to express one of two possible states.

JSON object

In the JSON serialization, an object structure is represented as a pair of curly brackets surrounding zero or more name/value pairs (or members). A name is a string. A single colon comes after each name, separating the name from the value. A single comma separates a value from a following name. In JSON-LD the names in an object must be unique.

In the internal representation a JSON object is described as a map (see [[INFRA]]), composed of entries with key/value pairs.

In the Application Programming Interface, a map is described using a [[WEBIDL]] record.

null

The use of the null value within JSON-LD is used to ignore or reset values. A map entry in the @context where the value, or the @id of the value, is null, explicitly decouples a term's association with an IRI. A map entry in the body of a JSON-LD document whose value is null has the same meaning as if the map entry was not defined. If @value, @list, or @set is set to null in expanded form, then the entire JSON object is ignored.

number

In the JSON serialization, a number is similar to that used in most programming languages, except that the octal and hexadecimal formats are not used and that leading zeros are not allowed. In the internal representation, a number is equivalent to either a long or double, depending on if the number has a non-zero fractional part (see [[WEBIDL]]).

scalar

A scalar is either a string, number, true, or false.

string

A string is a sequence of zero or more Unicode (UTF-8) characters, wrapped in double quotes, using backslash escapes (if necessary). A character is represented as a single character string.

Terms imported from [[[RFC3987]]] [[RFC3987]]

IRI: The absolute form of an IRI containing a scheme along with a path and optional query and fragment segments.
IRI reference: Denotes the common usage of an Internationalized Resource Identifier. An IRI reference may be absolute or relative. However, the "IRI" that results from such a reference only includes absolute IRIs; any relative IRI references are resolved to their absolute form.
relative IRI reference: A relative IRI reference is an IRI reference that is relative to some other IRI, typically the base IRI of the document. Note that properties, values of @type, and values of terms defined to be vocabulary relative are resolved relative to the vocabulary mapping, not the base IRI.

Terms imported from [[[RDF11-CONCEPTS]]] [[RDF11-CONCEPTS]], [[[RDF-SCHEMA]]] [[RDF-SCHEMA]], and [[[LINKED-DATA]]] [[LINKED-DATA]]

base IRI: The base IRI is an IRI established in the context, or is based on the JSON-LD document location. The base IRI is used to turn relative IRI references into IRIs.
blank node: A node in a graph that is neither an IRI, nor a literal. A blank node does not contain a de-referenceable identifier because it is either ephemeral in nature or does not contain information that needs to be linked to from outside of the linked data graph. In JSON-LD, a blank node is assigned an identifier starting with the prefix _:.
blank node identifier: A blank node identifier is a string that can be used as an identifier for a blank node within the scope of a JSON-LD document. Blank node identifiers begin with _:.
dataset: A dataset representing a collection of RDF graphs including exactly one default graph and zero or more named graphs.
datatype IRI: A datatype IRI is an IRI identifying a datatype that determines how the lexical form maps to a literal value.
default graph: The default graph of a dataset is an RDF graph having no name, which may be empty.
graph name: The IRI or blank node identifying a named graph.
language-tagged string: A language-tagged string consists of a string and a non-empty language tag as defined by [[BCP47]]. The language tag must be well-formed according to section 2.2.9 Classes of Conformance of [[BCP47]]. Processors may normalize language tags to lowercase.
Linked Data: A set of documents, each containing a representation of a linked data graph or dataset.
RDF graph: A labeled directed graph, i.e., a set of nodes connected by directed-arcs. Also called linked data graph.
list: A list is an ordered sequence of IRIs, blank nodes, and literals.
literal: An object expressed as a value such as a string or number. Implicitly or explicitly includes a datatype IRI and, if the datatype is `rdf:langString`, an optional language tag.
named graph: A named graph is a linked data graph that is identified by an IRI or blank node.
node: A node in an RDF graph, either the subject and object of at least one triple. Note that a node can play both roles (subject and object) in a graph, even in the same triple.
object: An object is a node in a linked data graph with at least one incoming edge.
property: The name of a directed-arc in a linked data graph. Every property is directional and is labeled with an IRI or a blank node identifier. Whenever possible, a property should be labeled with an IRI.
The use of blank node identifiers to label properties is obsolete, and may be removed in a future version of JSON-LD.
Also, see predicate in [[RDF11-CONCEPTS]].
resource: A resource denoted by an IRI, a blank node or literal representing something in the world (the "universe of discourse").
triple: A component of an RDF graph including a subject, predicate, and object, which represents a node-arc-node segment of an RDF graph.
subject: A subject is a node in a linked data graph with at least one outgoing edge, related to an object node through a property.

JSON-LD Specific Term Definitions

active context

A context that is used to resolve terms while the processing algorithm is running.

compact IRI

A compact IRI has the form of prefix:suffix and is used as a way of expressing an IRI without needing to define separate term definitions for each IRI contained within a common vocabulary identified by prefix.

context

A set of rules for interpreting a JSON-LD document as described in the The Context section of JSON-LD 1.1, and normatively specified in the Context Definitions section of JSON-LD 1.1.

default language

The default language is the language used when a string does not have a language associated with it directly. It can be set in the context using the @language key whose value must be a string representing a [[BCP47]] language code or null. See the Context Definitions section of JSON-LD 1.1 for a normative description.

default object

A default object is a map that has a @default key.

base direction

The base direction is the direction used when a string does not have a direction associated with it directly. It can be set in the context using the @direction key whose value must be one of the strings `"ltr"`, `"rtl"`, or null. See the Context Definitions section of JSON-LD 1.1 for a normative description.

embedded context

An embedded context is a context which appears as the @context entry of one of the following: a node object, a value object, a graph object, a list object, a set object, the value of a nested property, or the value of an expanded term definition. Its value may be a map for a context definition, as an IRI, or as an array combining either of the above.

scoped context

A scoped context is part of an expanded term definition using the @context entry. It has the same form as an embedded context. When the term is used as a type, it defines a type-scoped context, when used as a property it defines a property-scoped context.

expanded term definition

An expanded term definition is a term definition where the value is a map containing one or more keyword keys to define the associated IRI, if this is a reverse property, the type associated with string values, and a container mapping. See the Expanded Term Definition section of JSON-LD 1.1 for a normative description.

frame

A JSON-LD document, which describes the form for transforming another JSON-LD document using matching and embedding rules. A frame document allows additional keywords and certain map entries to describe the matching and transforming process.

frame object

A frame object is a map element within a frame which represents a specific portion of the frame matching either a node object or a value object in the input. See the Frame Objects section of JSON-LD 1.1 for a normative description.

graph object

A graph object represents a named graph as the value of a map entry within a node object. When expanded, a graph object must have an @graph entry, and may also have @id, and @index entries. A simple graph object is a graph object which does not have an @id entry. Note that node objects may have a @graph entry, but are not considered graph objects if they include any other entries. A top-level object consisting of @graph is also not a graph object. Note that a node object may also represent a named graph if it includes other properties. See the Graph Objects section of JSON-LD 1.1 for a normative description.

id map

An id map is a map value of a term defined with @container set to @id. The values of the id map must be node objects, and its keys are interpreted as IRIs representing the @id of the associated node object. If a value in the id map contains a key expanding to @id, its value must be equivalent to the referencing key in the id map. See the Id Maps section of JSON-LD 1.1 for a normative description.

implicitly named graph

A named graph created from the value of a map entry having an expanded term definition where @container is set to @graph.

included block

An included block is an entry in a node object where the key is either `@included` or an alias of `@included` and the value is one or more node objects. See the Included Blocks section of JSON-LD 1.1 for a normative description.

index map

An index map is a map value of a term defined with @container set to @index, whose values must be any of the following types: string, number, true, false, null, node object, value object, list object, set object, or an array of zero or more of the above possibilities. See the Index Maps section in JSON-LD 1.1 for a formal description.

JSON literal

A JSON literal is a literal where the associated datatype IRI is rdf:JSON. In the value object representation, the value of @type is @json. JSON literals represent values which are valid JSON [[RFC8259]]. See the The `rdf:JSON` Datatype section in JSON-LD 1.1 for a normative description.

JSON-LD document

A JSON-LD document is a serialization of an RDF dataset. See the JSON-LD Grammar section in JSON-LD 1.1 for a formal description.

JSON-LD Processor

A JSON-LD Processor is a system which can perform the algorithms defined in JSON-LD 1.1 Processing Algorithms and API. See the Conformance section in JSON-LD 1.1 API for a formal description.

JSON-LD internal representation

The JSON-LD internal representation is the result of transforming a JSON syntactic structure into the core data structures suitable for direct processing: arrays, maps, strings, numbers, booleans, and null.

JSON-LD value

A JSON-LD value is a string, a number, true or false, a typed value, or a language-tagged string. It represents an RDF literal.

keyword

A string that is specific to JSON-LD, described in the Syntax Tokens and Keywords section of JSON-LD 1.1, and normatively specified in the Keywords section of JSON-LD 1.1,

language map

A language map is a map value of a term defined with @container set to @language, whose keys must be strings representing [[BCP47]] language codes and the values must be any of the following types: null, string, or an array of zero or more of the above possibilities. See the Language Maps section of JSON-LD 1.1 for a normative description.

list object

A list object is a map that has a @list key. It may also have an @index key, but no other entries. See the Lists and Sets section of JSON-LD 1.1 for a normative description.

local context

A context that is specified with a map, specified via the @context keyword.

nested property

A nested property is a key in a node object whose value is a map containing entries which are treated as if they were values of the node object. The nested property itself is semantically meaningless and used only to create a sub-structure within a node object. See the Property Nesting section of JSON-LD 1.1 for a normative description.

node object

A node object represents zero or more properties of a node in the graph serialized by the JSON-LD document. A map is a node object if it exists outside of the JSON-LD context and:

it does not contain the @value, @list, or @set keywords, or
it is not the top-most map in the JSON-LD document consisting of no other entries than @graph and @context.

The entries of a node object whose keys are not keywords are also called properties of the node object. See the Node Objects section of JSON-LD 1.1 for a normative description.

node reference

A node object used to reference a node having only the @id key.

prefix

A prefix is the first component of a compact IRI which comes from a term that maps to a string that, when prepended to the suffix of the compact IRI, results in an IRI.

processing mode

The processing mode defines how a JSON-LD document is processed. By default, all documents are assumed to be conformant with this specification. By defining a different version using the @version entry in a context, publishers can ensure that processors conformant with JSON-LD 1.0 [[JSON-LD10]] will not accidentally process JSON-LD 1.1 documents, possibly creating a different output. The API provides an option for setting the processing mode to `json-ld-1.0`, which will prevent JSON-LD 1.1 features from being activated, or error if @version entry in a context is explicitly set to `1.1`. This specification extends JSON-LD 1.0 via the `json-ld-1.1` processing mode.

set object

A set object is a map that has an @set entry. It may also have an @index key, but no other entries. See the Lists and Sets section of JSON-LD 1.1 for a normative description.

term

A term is a short word defined in a context that may be expanded to an IRI. See the Terms section of JSON-LD 1.1 for a normative description.

term definition

A term definition is an entry in a context, where the key defines a term which may be used within a map as a key, type, or elsewhere that a string is interpreted as a vocabulary item. Its value is either a string (simple term definition), expanding to an IRI, or a map (expanded term definition).

type map

A type map is a map value of a term defined with @container set to @type, whose keys are interpreted as IRIs representing the @type of the associated node object; the value must be a node object, or array of node objects. If the value contains a term expanding to @type, its values are merged with the map value when expanding. See the Type Maps section of JSON-LD 1.1 for a normative description.

typed value

A typed value consists of a value, which is a string, and a type, which is an IRI.

value object

A value object is a map that has an @value entry. See the Value Objects section of JSON-LD 1.1 for a normative description.

vocabulary mapping

The vocabulary mapping is set in the context using the @vocab key whose value must be an IRI, a compact IRI, a term, or null. See the Context Definitions section of JSON-LD 1.1 for a normative description.