What is docker

Docker is a containerization engine that allows applications to be run in isolated environments, unaffected by the host operating system and local development environment. Many web-scale companies run a majority of their server infrastructure in containers now, due to the increased flexibility and composability of containerized application components.

Docker Playground:

https://labs.play-with-docker.com/

Examples:

https://blog.patricktriest.com/text-search-docker-elasticsearch/amp/?__twitter_impression=true