From: https://www.elastic.co/products

Elastic provides a growing platform of open source projects and commercial products designed to search, analyze, 
and visualize your data, allowing you to get actionable insight in real time. Our products are architected to seamlessly work together as a standalone solution or easily integrate into your existing infrastructure.

At the heart of it all are Elasticsearch, Logstash, and Kibana, three open source projects that, when combined, 
are known as the ELK stack. Our commercial products, Shield and Marvel, add even more value to our open source solutions, offering a growing list of capabilities, including security and monitoring.