What's a RDF triple?

Question

In layman\'s terms, what\'s a RDF triple?

Answer 1

RDF is a Language, i.e., a system of signs, syntax, and semantics for encoding and decoding information (data in some context).

In RDF, a unit of observation (Data) is represented by a sentence that consists of three parts: subject, predicate, object. Basically, this is the fundamental structure of natural language speech.

The sign used to denote entities (things) participating in entity relationships represented by RDF is an IRI (which includes HTTP URIs). Each subject and predicate (and optionally, object) component of an RDF sentence is denoted by an IRI.

The syntax (grammar) is abstract (meaning it can be represented using a variety of notations) in the form of subject, predicate, and object arrangement order.

The semantics (the part overlooked most often) is all about the meaning of the subject, predicate, and object roles in an RDF statement.

When you use HTTP URIs to denote RDF statement subject, predicates, and (optionally) objects, you end up with structured data (collections of entity relationship types) that form a web -- just as you have today on the World Wide Web.

When the semantics of a predicate (in particular) in an RDF statement are both machine and human comprehensible you have a web of entity relationship types that provide powerful encoding of information that is a foundation for knowledge (inference and reasoning).

Here are examples of simple RDF statements:

{
    <#this>             a  schema:WebPage                          .
    <#this>  schema:about  dbpedia:Resource_Description_Framework  .
    <#this>  skos:related  <https://stackoverflow.com/questions/30742747/convert-a-statement-with-adjective-in-rdf-triple/30836089#30836089>   . 
}

I've used braces to enclose the examples so that this post turns into a live RDF-based Linked Data demonstration, courtesy of relative HTTP URIs and the # based fragment identifier (indexical).

Results of the RDF statements embedded in this post, courtesy of nanotation (embedding RDF statements wherever text is accepted):

1. Basic Entity Description Page -- Each Statement is identified by a hyperlink that resolves to its description (subject, predicate, object parts)
2. Deeper Faceted Browsing Page -- Alternative view that lends itself to deeper exploration and discovery by following-your-nose through the hyperlinks that constitute the data web or web of linked data.
3. Description of an embedded statement -- About a specific RDF statement.

Here's the visualization generated from the triples embedded in this post (using our Structured Data Sniffer Browser Extension, using RDF-Turtle Notation:

Answer 2

An RDF file should parse down to a list of triples.

A triple consists of a subject, a predicate, and an object. But what do these actually mean?

The subject is, well, the subject. It identifies what object the triple is describing.

The predicate defines the piece of data in the object we are giving a value to.

The object is the actual value.

From: http://www.robertprice.co.uk/robblog/archive/2004/10/What_Is_An_RDF_Triple_.shtml

Answer 3

RDF Triple is an actual expression that defines a way in which you can represent a relationship between objects. There are three parts to a triple: Subject, Predicate and Object (typically written in the same order). A predicate relates subject to object.

Subject ----Predicate---> Object

More useful information can be found at:

http://www.w3.org/TR/rdf-concepts/

Answer 4

A simple answer can be that an RDF triple is a representation of some knowledge using RDF data model. This model is based upon the idea of making statements about resources (in particular web resources URIs) in the form of subject–predicate–object expressions. RDF is also a standard model for data interchange on the Web. RDF has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time without requiring all the data consumers to be changed. I recommend this article to know how: https://www.w3.org/DesignIssues/RDF-XML.html

Answer 5

One can think of a triple as a type of sentence that states a single "fact" about a resource. First of all to understand RDF Triple you should know that each and every thing in RDF is defined in terms of URI http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#dfn-URI-referenceor blank node http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#dfn-blank-node.

An RDF Triple consists of three components :- 1) Subject 2) Predicate 3) Object For ex :- Pranay hasCar Ferrari Here Subject is Pranay, hasCar is a predicate and Ferrari is a object. This are each defined with RDF-URI. For more information you can visit :- http://www.w3.org/TR/owl-ref/

Answer 6

I think the question needs to be split into two parts - what is a triple and what makes an "RDF triple" so special?

Firstly, a triple is, as most of the other commenters here have already pointed out, a statement in "subject/predicate/object" form - i.e. a statement linking one object (subject) to another object(object) or a literal, via a predicate. We are all familiar with triples: a triple is the smallest irreducible representation for binary relationship. In plain English: a spreadsheet is a collection of triples, for example, if a column in your spreadsheet has the heading "Paul" and a row has the heading "has Sister" and the value in the cell is "Lisa". Here you have a triple: Paul (subject) has Sister(predicate) Lisa (literal/object).

What makes RDF triples special is that EVERY PART of the triple has a URI associated with it, so the everyday statement "Mike Smith knows John Doe" might be represented in RDF as:

uri://people#MikeSmith12 http://xmlns.com/foaf/0.1/knows uri://people#JohnDoe45

The analogy to the spreadsheet is that by giving every part of the URI a unique address, you give the cell in the spreadsheet its whole address space....so you could in principle stick every cell (if expressed in RDF triples) of the spreadsheet into a different document on a different server and reconstitute the spreadsheet through a single query.

Edit: This section of the official documentation addresses the original question.