The Java high-level REST client is built on the top of the low-level REST client. It is responsible for the serialization and deserialization of the request and response objects. According to the official announcement from Elasticsearch (available at https://www.elastic.co/guide/en/elasticsearch/client/java-api/7.0/transport-client.html), the transport client will be removed in version 8.0. Using the Java high-level REST client should be the preference. Similarly to how we presented the low-level REST client, we'll target only the workflow of the Java high-level REST client.