Docker became an essential component of most worldwide enterprises' configuration management systems. The fundamental reason for this is that Docker runs the applications with a high level of abstraction and security using Dockerfile.

Another reason for Docker's widespread popularity is because of its features. Organizations are using Docker to achieve high network availability, service continuity, and service provision with high scalability.

So, What is Docker all about?

Definition of Docker: Docker is an open-source container management Platform-as-a-Service (PaaS) product used to automate the process of building, deploying, and managing applications based on containerization technology (Namespaces & CGroups).

Features of Docker:
  1. Easy and faster configuration
  2. Application Isolation
  3. Security Management
  4. High Scalability and Productivity
  5. Infrastructure Dependent
Moving on, we come across various terms such as Containers, Images, and so on. Let's go through these first, then go on to the other topics.

What is a Docker Container: A container is a lightweight, small, standalone executable package of a software execution environment that make shared use of the OS kernel and run it in isolation from one another. 

In other words, Container is a software package that has all the dependencies required to run an application. It is also called an instance of the Docker image.

What is Docker Image: A docker image is a read-only file with a bunch of instructions. When these instructions are executed, it creates a Docker container.

In other words, Docker Image is just a template of instructions used to create containers. This includes all of the Operating System files, as well as application code and any required supporting libraries. 

People frequently inquire about the distinction between Docker Image and Docker Container. We could claim that it is not an apple-to-apple comparison. However, I respond to them as follows:


Docker containers and images, in general, are comparable to Java classes and objects. A class is a blueprint for how to generate objects, similar to how a Docker image is used to create a Docker container.

A single class can be instantiated into several objects, in the same way, that a Docker image can be used to launch multiple containers.