ELK Stack (or the Elastic Stack) stands for Elasticsearch, Logstash, and Kibana is used for analyzing any type of structured and unstructured data source in real time. Elasticsearch is a NoSQL database JSON-based Lucene search and analytics engine; Logstash is a data collection and log pipeline tool that accepts inputs from various sources, parses the logs, executes different transformations, and exports the data to various targets; Kibana is a visualization or user interface layer that works on top of Elasticsearch proxied through Nginx.