What is Docker & Why is it Getting Popular?

Published on:
November 28, 2023

Docker allows you to package an application with all its dependencies into a standardized unit for software development.” - Docker.

Being in IT for the last 5 years, you might have heard of the container platform Docker. Docker and containers are a new approach to executing software that changes how software is developed and delivered. Solomon Hykes co-founded Docker, a company that aimed to make containers easier to use, five years ago. 

The buzz grew into a roar with the June 2014 release of Docker 1.0. And it's just grown louder over time. Docker is gaining popularity, and many firms have begun to include it in their development process. But what’s the reason behind it? Today, we will walk you through the nitty-gritty of Docker and why it is getting adopted rapidly.

What is Docker?

Before we delve into Docker, let’s look at what containers are. A container is a sort of process that is separate from other processes. Containers are given resources that no other process can access and cannot access any resources that have not been specifically allotted to them.

Why is it a big deal?

Processes that are not "containerized" can request access to any file on disk or network socket from the operating system.

There was no reliable, guaranteed mechanism to isolate a process to its resources until containers were widely accessible. A fully functioning container has no method of reaching outside its resource "sandbox" and interacting with resources not expressly given to it.

For example, 2 containers operating on the same machine may as well be running on two entirely distinct systems thousands of kilometers apart. They are completely and effectively separated from one another.

The road to cloud-native begins with containerizing your application and its dependencies. Containers are also cloud-native technologies, contributing to the Cloud Native Computing Foundation's (CNCF) mission of cultivating and sustaining an ecosystem of open-source, vendor-neutral initiatives.

As Craig McLuckie from Google said, “This containers revolution is changing software consumption. It’s redefining into a lightweight, portable unit/atom that is easier to comprehend. It’s a lane to dynamic management & systems.”

Now that you understand, containers enter Docker. It is open-source software that allows programs to be deployed within virtual containers. Containerization enables distinct applications to operate in various difficult contexts. Docker lets the WordPress content management system work flawlessly on Windows, Linux, and macOS platforms.

Docker vs. Virtual Machine

While Docker and virtual machines accomplish comparable functions, they differ greatly in speed, OS support & portability.

The primary distinction is that Docker containers share the host's operating system, whereas virtual machines run a guest operating system on top of the host system. This mode of operation impacts performance, hardware requirements, and OS support.

Here are some more differences between containers like Docker and virtual machines. 

  • Better Developer Productivity: Containers are easier and faster to install, provision, and restart than virtual machines. As a result, they are a superior choice for CI (continuous integration) and CD (continuous delivery) pipelines. They are also more suited for Agile and DevOps procedures.
  • More Lightweight: Containers simply contain the processes and their dependencies. VMs, on the other hand, have a second OS instance. As a result, a container is lighter than its virtual machine equivalent for the identical application operation.

Superior Resource Utilization: Containers, like virtual machines, allow several copies of an application process to execute on the same hardware simultaneously. They, on the other hand, use fewer resources.

Docker Core Components

The Docker tool comprises several components, each of which plays a vital function in the platform. Let’s take a look.

Docker Engine

The Docker Engine (DE), installed on the host machine, is the heart of the Docker system. It is a lightweight runtime system and the underlying client-server technology that allows containers to be created and managed.

Docker Engine includes three parts:

  • Server - The Docker daemon (Dockerd) is responsible for generating and managing containers on the server.
  • Rest API - Allows applications to communicate with Docker & directs Dockerd on what to do.

Command Line Interface (CLI) - Docker instructions are executed via the Command Line Interface (CLI).

Docker Images

Docker images are container construction templates. Docker images, like virtual machine snapshots, are immutable, read-only files that contain the source code, libraries, dependencies, tools, and any other files required to run an application. 

A Dockerfile, which provides precise instructions for generating a specific Docker image, is used to generate each image. Once you have mastered producing Docker images using Dockerfiles, you can construct images and custom containers more quickly and easily.


A Dockerfile is a script that contains instructions for creating a Docker image. The operating system, languages, Docker environment variables, file locations, network ports, and other components required to run the image are all specified in these instructions. All the commands in the file are automatically grouped and executed.

Docker Hub

Docker Hub is Docker's largest cloud-based repository of container images. It hosts approximately 100,000 images created by open-source projects, software vendors, and the Docker community.

The platform enables you to ship apps anywhere swiftly, connect with peers, and automate builds for speedier integration into a development pipeline. Developers, like GitHub, push and pull container images from Docker Hub and choose whether to make them public or private.

Docker Volumes

Instead of adding additional layers to an image, utilizing Docker volumes is a better way to retain data created by a running container. Users can use this useful tool to preserve data, transfer it amongst containers, and mount it to new ones. The container life cycle does not affect Docker volumes because they are kept on the host.

Docker Compose

Docker Compose is a handy tool for simultaneously launching and managing numerous containers. It connects many containers required for collaboration and controls them with a single coordinated command. Docker Compose is a command-line tool for launching, executing, and communicating with containers. It is accomplished using a YAML file to configure the application's services.

Docker Desktop

Docker Desktop, formerly known as Docker for Windows and Docker for Mac, is a program that allows you to create and operate containers on Windows and Mac in minutes. It is a straightforward installation and configuration of the entire Docker development environment. 

Docker CLI Client, Docker Compose, Docker Engine, Docker Content Trust, Credential Helper & Kubernetes are all included. The tool creates and shares containerized apps and microservices across any cloud platform in various languages and frameworks.

Why do companies embrace Docker containers?

Docker has been the most popular container platform since its initial release in June 2014. As the Co-founder of Qovery, Morgan Perry, says - “It's extremely easy for developers to create, manage, scale & deploy their apps securely using Docker.

As research reports, 2/3 of Companies that test out docker adopt it. So, why is Docker so popular among companies? Let’s take a look.

Easy Usage

Docker's success stems in large part from its ease of use. Docker may be learned quickly due to the number of resources for constructing and managing containers. Because Docker is open-source, all you need to get started is a computer with a supported operating system, such as Linux, Virtualbox, Docker for Mac/Windows, or generic container support.

Easy to Deploy

A docker container may be easily deployed to the cloud. Docker, in particular, makes it simple to construct local development environments that function just like a live server for CI/CD run several development environments from the same host with different apps, operating systems, and configurations. Organizations that use Docker for CI/CD have reported spending 50% less time dealing with security concerns.

Simplicity and Speed

Docker is well-known for its ability to streamline the process. It enables customers to take their configuration, write it, and distribute it seamlessly. Docker is compatible with a broad range of environments. Therefore, the application environment is no longer a barrier.

Continuous Deployment and Testing

Docker makes it possible to have consistent environments from development to production. Suppose a developer has to upgrade a product throughout its release cycle. 

In that case, he may do it by making the necessary modifications to the Docker container, testing them, and then implementing the same changes into existing containers. They can easily use Docker Hub to search and share container images with the team. Private repositories need a membership plan, whereas public repositories are free.

Multi-Cloud Platforms and Isolation

One of Docker's primary selling points is portability. Amazon Web Services and Google Compute Platform have adopted it as a genuine service provider, demonstrating its supremacy. Docker is well-known for isolating your apps and resources. It gives containers their resources and encourages them to run within their containers.

Comparing docker to other containerization tools

So far, we have learned what docker is and why it’s so popular. Now, we'll know how Docker compares to Kubernetes and Jenkins and the contrasts between them.

Docker vs. Kubernetes

Kubernetes is an open-source container orchestration technology, whereas Docker is a platform for constructing and operating containers. These two technologies cannot be compared as Docker creates containers while Kubernetes maintains them on a large scale.

Docker offers a simple and efficient approach to running and managing containers, but Kubernetes offers more complex capabilities, such as automated container deployment, scalability, and self-healing.

On the other hand, Docker has an orchestration mechanism called Docker Swarm. Having evolved from the Docker project, Kubernetes has emerged as the de facto Docker orchestration domain of choice.

Docker vs. Jenkins

Comparing Docker with Jenkins is like comparing a cat and a dog. Docker and Jenkins serve fundamentally distinct purposes. Hence, they cannot be compared. Jenkins is a central automation system for the CI/CD development approach, in which developers continually send tiny portions of work to avoid merge problems. On the other hand, Docker is a system for containerization.

Using its plugins, Jenkins provides an intuitive interface for creating and managing numerous CI/CD pipelines. For software testing, anyone may create Docker images and run Docker containers using the Jenkins CI/CD pipeline.

Best Docker Extensions

Gabriel N. Schenker, in his book ‘Learn Docker - Fundamentals of Docker 18. x’ says, “Companies that implement containers & containerize their traditional mission-critical apps have witnessed savings of around 50% in overall maintenance costs & a 90% or more reduction in deploying new versions of those apps.”

It implies that Docker is an essential tool to master since it can help you automate many tasks and business operations. So, let's look at some useful Docker extensions that can improve the efficiency and productivity of your Docker process.

  • JFrog - If you've previously dealt with Docker images, you'll occasionally need to work with open-source ones. In some cases, this addition comes in handy.
  • Portainer - Portainer provides a web-based interface for managing Docker-related resources like containers, images, volumes, networks, etc.
  • Disk Usage - Disk consumption is a Docker addon that provides developers with data about their Docker disk consumption.
  • Drone CI - DroneCI is an open-source tool that allows you to deploy the app to a selected host.
  • Okteto - Okteto is a valuable tool that boosts productivity and enjoyment by delivering pre-configured surroundings. It saves you time from manually configuring environments.

Docker Use Cases

Docker has several uses. Let’s go over a few.

To Try New Software

Docker allows you to test new software without having to install it manually. Docker is also beneficial when you need software to be available quickly. For example, setting up a MySQL server is time-consuming and labor-intensive. It simply takes one command in the Docker CLI to do this.

To Know More about the CLI

Although Docker can run on any machine, it was developed especially for Linux. As a result, we suggest setting it on a Linux-based machine. It will allow you to learn more about system administration, command-line interfaces, and scripting.

To Reduce Incident Risk

If a Docker image is available, users may immediately undo any modifications in the event of a hardware failure. They simply need to copy the image backup to a new computer, and Docker will take care of the rest. Docker image backups are also useful when developers need to revert to an earlier version of a piece of software due to defects or incompatibility.


Docker is a powerful technology that streamlines the development process and allows developers to build, test, and deploy apps rapidly and efficiently. Docker streamlines & speeds your process while allowing developers to innovate using each project's preferred tools, app stacks & deployment environments.

With the growth of containerization technologies, it is clear that Docker will be in the spotlight for the foreseeable future. Want to explore Docker further? Let MarsDevs help. MarsDevs is our one-stop solution for all technical needs.

So, make the most of Docker with MarsDevs. Reach out to us today!


  1. What is so special about Docker?

Docker containers enable apps to be easily shuttled across environments since they encapsulate everything an application needs to execute.

  1. Is Docker Hard to Learn?

It may take some time to grasp Docker, but deploying your first container will be quick. Docker provides an easy-to-use Docker Desktop application and thorough documentation for beginners and advanced users to get started.

  1. Why is Docker becoming popular?

Docker is a well-known open-source containerization platform. It provides enhanced security, simplified management, and faster deployment.

  1. What is the best use of Docker?

Docker containers may be used as web servers or file servers. Docker containers for Nginx are also commonly used to build reverse proxy servers. Docker containers may be used to host and develop your Virtual Private Network (VPN).

  1. How is Docker used in real-time projects?

Dockers allow users to construct environment templates, so no effort is wasted setting environments because each environment is the same. Docker simplifies the management of large-scale systems & the creation of pipelines. It is a Linux application that is compatible with other operating systems.

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