What is the ELK stack?

The ELK stack is a popular log management and analytics pipeline composed of three open-source tools: Elasticsearch stores and indexes the data, Logstash ingests, transforms, and ships data from various sources into Elasticsearch, and Kibana provides a browser-based UI for visualizing and exploring the data stored in Elasticsearch. A modern variant is the Elastic Stack, which adds Beats (lightweight data shippers) to the ELK trio. The stack is widely used for centralized logging, application performance monitoring (APM), and security analytics (SIEM).