Schema.org is a reference website that publishes documentation and guidelines for using
structured data
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be co ...
mark-up on web-pages (called microdata). Its main objective is to standardize
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...
tags to be used by webmasters for creating rich results (displayed as visual data or infographic tables on search engine results) about a certain topic of interest. It is a part of the semantic web project, which aims to make document mark-up codes more readable and meaningful to both humans and machines.
History
Schema.org is an initiative launched on June 2, 2011, by
Bing
Bing most often refers to:
* Bing Crosby (1903–1977), American singer
* Microsoft Bing, a web search engine
Bing may also refer to:
Food and drink
* Bing (bread), a Chinese flatbread
* Bing (soft drink), a UK brand
* Bing cherry, a varie ...
,
Google
Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...
and
Yahoo!
Yahoo! (, styled yahoo''!'' in its logo) is an American web services provider. It is headquartered in Sunnyvale, California and operated by the namesake company Yahoo Inc., which is 90% owned by investment funds managed by Apollo Global Man ...
(operators of the world's largest
search engine
A search engine is a software system designed to carry out web searches. They search the World Wide Web in a systematic way for particular information specified in a textual web search query. The search results are generally presented in a ...
s at that time) to create and support a common set of schemas for structured data markup on web pages. In November 2011,
Yandex
Yandex LLC (russian: link=no, Яндекс, p=ˈjandəks) is a Russian multinational technology company providing Internet-related products and services, including an Internet search engine, information services, e-commerce, transportation, maps ...
(whose search engine is the largest in
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
) joined the initiative. They propose using the schema.org vocabulary along with the
Microdata Microdata can mean:
* Microdata (statistics), a statistical term for individual response data in surveys and censuses
* Microdata (HTML), a specification for semantic markup in HTML
* Microdata Corporation
Microdata Corporation was an American ...
JSON-LD
JSON-LD (JavaScript Object Notation for Linked Data) is a method of encoding linked data using JSON. 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 ...
formats to mark up website content with metadata about itself. Such markup can be recognized by
search engine spider
A Web crawler, sometimes called a spider or spiderbot and often shortened to crawler, is an Internet bot that systematically browses the World Wide Web and that is typically operated by search engines for the purpose of Web indexing (''web spid ...
s and other
parsers
Parsing, syntax analysis, or syntactic analysis is the process of analyzing a string of symbols, either in natural language, computer languages or data structures, conforming to the rules of a formal grammar. The term ''parsing'' comes from L ...
, thus granting access to the meaning of the sites (see Semantic Web).
The initiative also describes an extension mechanism for adding additional properties.
In 2012, the
GoodRelations
GoodRelations is a Web Ontology Language-compliant ontology for Semantic Web online data, dealing with business-related goods and services. It handles the individual relationships between a buyer, a seller and the products and services offered. I ...
ontology
In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality.
Ontology addresses questions like how entities are grouped into categories and which of these entities exis ...
was integrated into Schema.org.
Public discussion of the initiative largely takes place on the
W3C
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working to ...
public vocabularies
mailing list
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. The term is often extended to include the people subscribed to such a list, so the group of subscribers is re ...
.
Much of the vocabulary on Schema.org was inspired by earlier formats, such as
microformat
Microformats (μF) are a set of defined HTML classes created to serve as consistent and descriptive metadata about an element, designating it as representing a certain type of data (such as contact information, geographic coordinates, events ...
s,
FOAF
FOAF (an acronym of friend of a friend) is a machine-readable ontology describing persons, their activities and their relations to other people and objects. Anyone can use FOAF to describe themselves. FOAF allows groups of people to describe soc ...
, and
OpenCyc
Cyc (pronounced ) is a long-term artificial intelligence project that aims to assemble a comprehensive ontology and knowledge base that spans the basic concepts and rules about how the world works. Hoping to capture common sense knowledge, Cyc fo ...
. Microformats, with its most dominant representative
hCard
hCard is a microformat for publishing the contact details (which might be no more than the name) of people, companies, organizations, and places, in HTML, Atom, RSS, or arbitrary XML. The hCard microformat does this using a 1:1 representation of ...
, continue (as of 2015) to be published widely on the web, where the deployment of Schema.org has strongly increased between 2012 and 2014. In 2015, Google began supporting the
JSON-LD
JSON-LD (JavaScript Object Notation for Linked Data) is a method of encoding linked data using JSON. 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 ...
format, and as of September, 2017 recommended using JSON-LD for structured data whenever possible.
Despite the advantages of using Schema.org, adoption remained limited as of 2016. A survey in 2016 of 300 US-based marketing agencies and B2C advertisers across
industries showing only 17% uptake.
Such
validator
A validator is a computer program used to check the validity or syntactical correctness of a fragment of code or document. The term is commonly used in the context of validating HTML,Tittel, Ed, and Mary C. Burmeister. HTML 4 for Dummies. --For du ...
s as the soon-to-be-deprecated Google Structured Data Testing Tool, or more recent Google Rich Results Test Tool, Yandex Microformat validator, and Bing Markup Validator can be used to test the
validity
Validity or Valid may refer to:
Science/mathematics/statistics:
* Validity (logic), a property of a logical argument
* Scientific:
** Internal validity, the validity of causal inferences within scientific studies, usually based on experiments
** ...
of the data marked up with the schemas and Microdata. More recently,
Google Search Console
Google Search Console is a web service by Google which allows webmasters to check indexing status, search queries, crawling errors and optimize visibility of their websites.
Until 20 May 2015, the service was called Google Webmaster Tools. In ...
(formerly webmaster tools) has provided a report section for unparsable structured data. If any Schema code on a website is incorrect, it will show in this report.
Some schema markups such as Organization and Person are commonly used to influence search results returned by Google's Knowledge Graph.
Schema Types
There are a number of items that a web page can be marked up with using a Schema, with examples including:
* Article
* Breadcrumb
* Course
* Event
* FAQ
* LocalBusiness
* Logo
* Movie
* Product
* Recipe
* Review
* Video
Examples
Microdata
The following is an example of how to mark up information about a movie and its director using the Schema.org schemas and microdata. In order to mark up the data, the attribute itemtype along with the
URL
A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifie ...
of the schema is used. The attribute itemscope defines the scope of the itemtype. The kind of the current item can be defined by using the attribute itemprop.