schema.org is an Initiative initialized by big Search Engines Bing, Google and Yahoo [[schema.org](http://http://schema.org/docs/full.html]. The Goal is to bring Semantic Markup on propertary HTML5 Microdata Schemata. There is a small number of extensible Formats. This can be mapped to RDF without problem.
Initiative started by Bing, Google, Yahoo! on June 2, 2011.
Goal: Semantic Markup for Web Pages Content based on peropertary HTML5 Microdata Schemata
Search Engines, Web Crawler, an Browser recognize and understand schema.org Markup.
Small number of Formats (Extensible)
RDF mapping available.
extends Micradata Vocabulary with proprietary Category Hierarchies:
Creative works:
CreativeWork, Book, Movie, MusicRecording, Recipe, TVSeries...
AudioObject, ImageObject, VideoObject
Event
Organization
Person
Place, LocalBusiness, Restaurant ...
Product, Offer, AggregateOffer
Review, AggregateRating
and according Properties (Relations) with different Domain and Range
With RDFa one can encode anythin one wants and use any Vocabulory that is around there and one has not to relay on specialized predefined Vocabularies.
There is a Mapping between schema.org and RDFa. Both can be transcoded into each other.