The Wikipedia description of Elasticsearch is as follows:
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. Elasticsearch is developed in Java and is released as open source under the terms of the Apache License. Official clients are available in Java, .NET (C#), Python, Groovy and many other languages.
The given description does cover every aspect of what Elasticsearch is and also gives some details on how exactly it works and its core capabilities. It is distributed, scalable, enterprise-grade, and offers high performance querying and it does this by indexing the data available in HDFS. It also has rich API’s and also supports a variety of languages. Let's keep this section crisp as we have this entire chapter explaining Elasticsearch and its working...