Docker..

What is container?

A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings.

or we can also say that... A container is a bundle of Application, Application libraries required to run your application and the minimum system dependencies.

Docker is a containerization platform that provides easy way to containerize your applications, which means, using Docker you can build container images, run the images to create containers and also push these containers to container registries such as DockerHub, Quay.io and so on.

Or we can say that Docker is an open platform for developing, shipping, and running applications Docker enables you to separate your applications from your infrastructure so you can deliver software quickly.

In simple words, we can also say that containerization is a concept or technology and Docker Implements Containerization.