What is a Docker Container?

    Docker container technology came into existence in the year of 2013. The technology available from Docker and its open-source project, Moby, is leveraged by big tech giants, cloud providers, and data centre vendors. Moreover, the major open-source serverless frameworks also inhabit Docker container technology. In this article, we will talk about this technology in detail and expand our knowledge base. However, before diving into the core topic, it is vital to grasp the concept of containers first.

    What is a Container?

    Consider a container as a standard unit of software that encapsulates code along with the dependencies so that applications can run easily and quickly in different environments. A container consists of Docker container images. These images are executable packages of software. Moreover, they are inclusive of code, system tools, libraries, runtime, and the settings that are required to run an application. When we talk about container images, they turn out to be containers at the run time. Whereas, Docker container images turn out to be containers while running on the Docker Engine. You can easily use it on both Windows as well as Linux-based applications. Another interesting fact is that many containers are unique and they hibernate themselves from the software and guarantee that they work uniformly even after confronting several obstacles in the development or staging phase. There are three essential features of Docker containers that are as follows:

    • Lightweight : Containers in general do not need an operating system per application. It further helps to lessen service costs as well as drives higher service efficiency
    • Standard : Docker helps to build an industry standard for containers, so that they become portable.
    • Secure : All the applications are safe in containers due to their reliable isolation capabilities.

    Now that you have a basic understanding of Docker, Docker container images, let us now make you familiar with Docker containers now.

    Docker Containers

    At present, the popularity of Docker containers is soaring high in the tech world. This technology is unique in its own way. It primarily focuses on fulfilling the requirements of system operators and developers to separate application dependencies from infrastructure. Let us now look at the concepts of containers and virtual machines. Both containers and virtual machines inhabit the same allocation benefits but have different functions. In the case of containers, they are portable and virtualize the OS in place of hardware. Here is an in-depth analysis of containers and virtual machines:

    • Containers

    Containers encapsulate code and the associated dependencies so that the applications can run smoothly. Various containers can run simultaneously on the same device. Moreover, you can share the operating system kernel with other containers too. They consume much less space when compared to virtual machines. Additionally, they have the ability to tackle more applications at the same time.

    • Virtual Machines

    Virtual machines are physical hardware that turns one server into several servers. Hypervisor carries out the task to permit several virtual machines to run on a single machine. Furthermore, every virtual machine consists of a copy of OS, libraries, applications, binaries, that make up for several GBs of disk space. Now that you have understood both the concepts separately, you also need to understand that containers and virtual machines guarantee a major advantage when clubbed together. Both the containers and the virtual machines offer you enhanced flexibility to deploy as well as manage several applications. Docker containers are instilled with several features. One of them is Docker Engine. Let us make you familiar with a new concept known as Docker Engine in the next section.

    Docker Engine

    Docker Engine is basically a container runtime that can run on various Windows server operating systems as well as Linux distributions, including CentOS, Fedora, RHEL, Oracle Linux, SUSE, Ubuntu. Docker is a simple tool and a universal packaging way to encapsulate all the dependencies of an application in a container. That application is then run on the Docker Engine. Docker Engine helps containerized applications to run on various platforms and infrastructures. This way, developers can carry out the work from anywhere. Here are some of the features of Docker Engine that help you to work in a better way:

    • Flexibility to Choose an OS : Docker Engine is able to work with various operating systems. It also works across hybrid or multi-cloud systems.
    • Innovative : With Docker Engine, the developers get the opportunity to quickly manifest their ideas into reality.
    • Security : Docker Engine is packed with security. It consists of FIPS 140-2 validation, therefore, the users can run the applications in different environments.

    Moreover, there are several other capabilities that Docker containers inhabit:

    • Backed up by containerd
    • Docker CLI
    • BuildKit

    Here is a detailed explanation of each capability: Backed up by containerd Docker Engine is powered by containerd. It is a project established by the Cloud Native Computing Foundation. The core work of containerd is to implement the Kubernetes container runtime interface, also known as CRI. Docker CLI It is the most widely used way to interface with Docker Containers. Docker CLI is a simple yet powerful client that helps to simplify the process of managing container instances with commands. BuildKit When we talk about BuildKit, it's an open-source tool. It processes the Dockerfile instructions and then forms a Docker image, which is a time-taking process.Therefore, BuildKit helps to deliver various architectural enhancements. These enhancements help to make the process fast, portable, as well as precise. As we just talked about Docker CLI, you must know that Docker’s developer tools are a set of Docker CLI plugins. These plugins make the process of building, sharing, and testing containerised applications simpler. Docker developer tools escalates the building process of containerised applications. Our next segment is about the features associated with such integrated developer tools. Take a look.

    Integrated Developer Tools

    With Docker, you can easily build applications and share them with any platform of your choice. Take a look at the impressive set of features that the integrated developer tools inhabit:

    • Integration with Docker Hub : You can easily build Docker images on the Docker desktop and later store them in the Docker hub. Along with that, you have the option to configure a CI/CD container workflow with some automated actions and builds after you push every time to the Docker hub registry.
    • Open images : Docker is extremely popular because of its several features. Docker build is one of them. You can quickly create as well as share Docker container images on various CPU and OS architectures.
    • Multi-environment support : You can switch easily between Kubernetes and Docker working environments. With the help of simple commands, you can test, stage, and produce.


    In a nutshell, Docker helps to ease down the work-life of the developers. Docker tools improvise the Dev Workflows and follow industry standards to containerize apps. With Docker’s subscription plan, you get guaranteed security and power-packed features! This article aims to give you insights into Docker and Docker containers. We hope that the information presented here helps you to clearly understand the concept of Docker Containers.

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