What is a Docker?

A Docker is defined as the platform for containerizing the applications to isolate it from each other in order to ensure high availability and more efficiency irrespective of the environments such as Development, Testing or Production. All the application related dependencies such as libraries, jar files, server related configurations, infrastructure-related elements will be packaged and formed as container called containerized application which does not need any dependency and works independently. It ensures the application to be run irrespective of the external factors. Containers in Docker have support from Docker Engine and Host Operating System to support all the operational or infrastructural related dependencies.