Docker Containers V/s Virtual Machines
Docker Containers Vs Virtual Machines


In today’s world, almost every organization faces some issues in transforming their business digitally, like the diverse portfolio of on-premises-bases infrastructure, cloud, and applications. But Docker comes up with the revolutionary change in the day to day life of the organizations!

Docker Containers

Docker solves this obstacle and issues of every organization using a container platform that can bring traditional applications and microservices (which are built on Linux, mainframe, and Windows) into a secure and automated supply chain.

Docker is a virtualization technology and a software development tool that makes it easy to develop, deploy, and manage all the applications via container service. Here, container refers to a stand-alone, lightweight, executable package of software that includes all the configuration files, dependencies, libraries, and other necessary parts to operate the application.

Containers provide the following benefits: 

  • Reduced resources of IT management
  • Snapshots Reduced size 
  • Quicker spinning up apps
  • Simplified and Reduced security updates
  • It uses less code to transfer, migrate, and upload workloads

Virtual Machines

On the other hand, Virtual machines perform tasks which otherwise performed in the host environment. Virtual machines are isolated or separated from the rest of the system; the software or application inside the virtual machine can not tamper with the OS or host computer. 
And therefore, implementing tasks such as testing of operating systems and accessing virus-infected data is done using virtual machines.

We can also define a virtual machine as; It is a computer file or software usually known as a guest, or an image that is created within a computing environment called the host.

Differences between Docker Container and Virtual Machine

1. OS Support and Architecture

Virtual machines have host Operating System and the guest Operating System inside each VM. Guest Operating System can be any Operating System, like Windows or Linux, irrespective of host Operating System. In contrast, Docker containers host on a single physical server with a host Operating System, which shares among them. Sharing the host Operating System between containers makes them light and increases the boot time. Docker containers are considered suitable to run multiple applications over a single Operating System kernel; whereas, virtual machines are needed if the applications or services required to run on different Operating System.

2. Security

Virtual machines are stand-alone with their security and kernel features. Therefore, applications or software needing more security and privileges run on virtual machines. 
On the other side, providing root access to applications and running them with administrative premises is not recommended in Docker containers since containers share the host kernel. The docker’s container technology has access to the kernel subsystems; thus, a single infected application can hacking the entire host system.

3. Portability

The Virtual machines are isolated or separated from their OS, and therefore, they are not ported across multiple platforms without suffering compatibility issues. On the development level, if an application is to be tested on very different platforms, then Docker containers must be contemplated. 
Since Docker containers do not need a guest OS, they can be easily ported across different platforms. Also, its packages are self-contained and can run applications in any environment. As the Docker containers are lightweight so they can be easily deployed in servers and can be stopped and started in very less time compared to virtual machines.

4. Performance

The Docker containers is less resource-intensive than virtual machines as the Virtual Machine needs to load the entire OS to start whereas the Docker Container uses lightweight architecture.
In VMs, resources like Memory, I/O, and CPU may not be allocated permanently to containers, unlike in the case of Docker containers, where the resource usage with the load or traffic. 
Scaling up and duplicating containers is simple and easy as compared to virtual machines because there is no need to install an OS in them.
Apart from the major differences, some other differences are summarized below: 

Docker ContainerVirtual Machines
Time to BootDocker gets Boots in a few seconds.It takes a few minutes for Virtual machines to boot.
It Runs onDockers use the execution engine.Virtual machines make use of the hypervisor.
Efficiency of MemoryNo space is needed to virtualize, hence less memory. Requires entire OS to be loaded before starting the surface, so less efficient. 
Isolation/InterferenceIn Docker, Prone to adversities as no provisions for isolation systems.In VMs, Interference possibility is minimum because of the efficient isolation mechanism.
DeploymentDeploying is easy in Docker as only a single image, containerized can be used across all platforms. In VMs, Deployment is lengthy in comparison to Docker as separate instances are responsible for execution.
UsageIt has a complex usage mechanism consisting of both the third party tools and docker managed tools.

Tools are easy to use and simpler to work with in Virtual Machines.

Comparison - Which one is better?

It is not fair to compare Docker and virtual machines because they are intended for different use. Docker can not be replaced with virtual machines, even if no doubt it is gaining momentum these days. In certain cases, the virtual machine is a better choice in spite of Docker. Virtual machines are considered as a suitable choice in a production environment (e.g., Linux OS) rather than the Docker containers because they run on their own OS. But if the applications need to be tested, then Docker is the good choice to go for, as it provides different OS platforms for the thorough testing of an application or the software.

Docker containers use docker-engine, whereas the virtual machines use the hypervisor. The Docker-engine makes the containers isolated, small, compatible, quick response, and high performance-intensive, as the host kernel is not shared. Docker containers have low overhead (in comparison with virtual machines) as they have compatibility to share the application libraries and a single kernel. Depends upon the kind of workload offered, Organizations are making use of the hybrid approach mostly as the choice between virtual machines and Docker containers.


Finally, Docker containers are not in conflict with virtual machines. They are both complementary tools for different usage and workloads. The Virtual machines are built for applications that are usually static and don’t change very often. In contrast, the Docker platform is built with a mindset to be more flexible so that containers can be updated frequently and easily.

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