ELKElastic

ELKElastic is not a widely used term in official Elastic documentation; it is commonly used informally to refer to the Elastic Stack, a group of open-source tools for searching, analyzing, and visualizing data in real time. The stack centers on Elasticsearch, Logstash, and Kibana (the ‘ELK’ in the original name), and is commonly augmented with Beats and other Elastic products. The Elastic Stack is developed by Elastic NV and is available in self-managed form and as a hosted service known as Elastic Cloud.

Elasticsearch is a distributed, RESTful search and analytics engine designed for horizontal scalability. Logstash is a data processing pipeline that ingests, transforms, and forwards data. Kibana provides visualization, exploration, and dashboards for data stored in Elasticsearch. Beats are lightweight shippers that collect and forward data from servers, applications, or networks.

In typical deployments, data flows from sources into Beats or Logstash, gets indexed and stored in Elasticsearch, and is explored and visualized through Kibana. The stack supports real-time search, observability, and security analytics, with additional features for machine learning, alerting, and monitoring through Elastic's proprietary components and licenses.

Licensing has evolved since the project’s early days. Elasticsearch and Kibana were originally released under Apache 2.0 but later transitions led to dual licensing, with Elastic providing proprietary features under the Elastic License in addition to open-source offerings. This has influenced forks and governance in the broader open-source ecosystem.

Common use cases include centralized log management, application observability, metrics and traces analysis, and search-based content applications. Deployments can be self-hosted on premises, in public or private clouds, or accessed via Elastic Cloud.