We just looked at how to perform basic CRUD operations. Elasticsearch supports a wide variety of operation types. Some operations deal with documents, that is, creating, reading, updating, deleting, and more. Some operations provide search and aggregations, while other operations are for providing cluster-related operations, such as monitoring health. Broadly, the APIs that deal with Elasticsearch are categorized into the following types of APIs:

• Document APIs
• Search APIs
• Aggregation APIs
• Indexes APIs
• Cluster APIs
• cat APIs

The Elasticsearch reference documentation has documented these APIs very nicely. In this book, we will not go into the APIs down to the last detail. We will conceptually understand, with examples, how the APIs can be leveraged to get the best out of Elasticsearch and the other components of the Elastic Stack.

We will look at the search and aggregation APIs in Chapter 3, Searching – What is Relevant, and Chapter 4, Analytics with Elasticsearch, respectively.

In the following section, we will cover the common API conventions that are applicable to all REST APIs.