Microdata is a standardized way to provide additional semantics in your web pages. Microdata consists of a group of name-value pairs. The groups are called items, and each name-value pair is a property.
Micro data has five global attributes which can be added to any element.
For example, to create a web page about movie "Star Wars", with information about the movie director, and so on.
<div itemscope itemtype="http://schema.org/Movie">
<h1 itemprop="name">Star Wars</h1>
<p>Director: <span itemprop="director">George Lucas</span></p>
<p>Genre: <span itemprop="genre">Science fiction</span></p>
<a href="/../movies/star-wars-trailer">Watch Trailer</a>