Elasticsearch is a search engine based on Lucene. It provides a distributed, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents. ElasticSearchis a free and open source distributed inverted index. So it’s a bunch of indexed documents in a repository. As well as it’s fast, incisive search against large volumes of data. And directly accessed to the data in the denormaliz document storage. Additionally in general distributable and highly scalable DB.