ElasticSearch – ElasticSearch Overview
Search Engines data model roots lies with schema free and document oriented databases, and as shown by the #nosql movement, this model proves to be very effective for building applications.
Elastic Search model is JSON, which slowly emerges as the de-facto standard for representing data these days. More over, with JSON, it is simple to provide semi-structured data with complex entities as well as being programming language natural with first level parsers.