Microdata is an international standard for the semantic markup of HTML pages. This specification allows data to be embedded in HTML documents and readable by machines. In plain English, microdata helps computers understand what the contents of your webpages say.
We're now going to define a webpage for the sake of this simple example:
Webpage — an independent part of a website; a document with its own unique address (URL).
The HTML-markup of this text may look something like this:
<div itemscope itemtype="http://webmaster.yandex.ru/vocabularies/term-def.xml"> <span itemprop="term">A webpage</span> — <span itemprop="definition">an independent part of a website; a document with its own unique address (URL).</span> </div>
The itemscope attribute is a key part of microdata. This attribute indicates that the contents of an HTML element are part of the same element. Nested HTML elements are denoted using the itemprop attribute and are properties of that element. The element given in the example above includes the term and definition properties; the value of the term property is “Webpage”. This markup means that web crawlers can easily recognize the term and definition in the text block.
The value of this property can also be text, a link (URL), date and/or time The property may also comprise an element containing embedded properties.
The type attribute is another important part of the itemscope element. The element type denotes what it describes: this could be a person, business, event, product, article etc. The element type should be specified within the itemtype attribute.
Yandex currently supports the following element types:
encyclopedic articles (for more information, please see our section on Markup for an encyclopedia article);
word definitions (for more information, please see our section on Markup for term definitions).