If you are a beginner to the world of full-text search and Elasticsearch, this book is for you. You will be guided through the basics of Elasticsearch, and you will learn how to use some of the advanced functionalities.
If you know Elasticsearch and have worked with it, you may find this book interesting as it provides a nice overview of all the functionalities with examples and description.
If you know the Apache Solr search engine, this book can also be used to compare some functionalities of Apache Solr and Elasticsearch. This may give you the knowledge about the tool, which is more appropriate for your use.