Elasticsearch, a modern search and analytics engine based on Apache Lucene, is central to the widely used ELK Stack (Elasticsearch, Logstash, and Kibana) for log analysis and search. Originally open-source, Elasticsearch transitioned to a proprietary dual license in 2021, prompting AWS to create the open-source alternative OpenSearch. This tutorial guides new users through the installation, configuration, and basic use of Elasticsearch, highlighting its NoSQL database structure which allows for flexible, schema-less data storage and powerful search capabilities through an extensive API. It also covers the creation and management of Elasticsearch clusters, a necessity for handling larger data sets and performance tuning, while acknowledging the challenges of scaling and maintaining such systems. For those preferring not to manage these complexities, services like Logz.io offer Elasticsearch-as-a-service, now rebranded as OpenSearch-as-a-service, providing additional features without the need for self-hosting.