Docker vs. Kubernetes

Docker and Kubernetes are two very popular technologies in containerization, a form of operating system virtualization in which applications are run in isolated software units called containers. 

Docker is a type of container “runtime,” or program that actually runs the container on a host operating system. Examples of other container runtimes include containerd, Windows Containers, and runC. Kubernetes is a platform for managing and orchestrating multiple containers. 

Orchestration platforms like Kubernetes and container runtimes like Docker are typically used together to accelerate microservices and streamline DevOps. Orchestration technologies, when used in conjunction with container runtimes, make application development and deployment faster, easier, and more bug-free. 

While Docker has historically been used with Kubernetes, this has changed—Kubernetes fully removed support for Docker as a runtime in version 1.24, released in 2022. However, Docker images still work seamlessly with Kubernetes, as modern container runtimes like containerd can still run them.

To fully understand both Docker and Kubernetes and the difference between them, it’s best to first understand containerization. 

Docker vs Kubernetes: What Is Containerization?

Containerization is the process of virtualizing operating systems by packaging application code into “containers” that make the applications self-contained and thus runnable on any type of infrastructure—i.e., inside virtual machines, in the cloud, or on bare metal—without needing to be refactored. 

Containerization allows developers to create and deploy applications faster and more securely because every application’s code is bundled with the related configuration files, libraries, and dependencies required to run it.

The concept of “containerization” is the idea that by breaking things down into sub-components, you can make them much easier to put together, take apart, and move around. This enables you to create larger things that are much greater than the sum of their parts. 

Although containerization technology has been around for decades, the advent of the Docker Engine in 2013 rapidly accelerated its adoption and made it mainstream. 

What Is Docker?

Docker is an open source platform for building and running applications inside of containers. The software that hosts the containers is called Docker Engine. Docker was invented in 2013 and is developed by Docker, Inc. 

Today, Docker is primarily used by developers for building and testing containers locally. In modern Kubernetes deployments, Docker is no longer used as the container runtime. Instead, Kubernetes-compatible runtimes such as containerd or CRI-O execute containers in production environments, while Docker remains useful for local development workflows.

What Is Kubernetes?

Kubernetes, also known as K8s, is an open source system for automating the deployment, scaling, and management of containerized applications. It was originally designed by Google and is now maintained by the Cloud Native Computing Foundation.

Advantages of Docker

Docker’s ability to package and run applications in isolated environments (i.e., containers) means application developers don’t have to rely on whatever is installed on the host. They can easily share containers while building applications and be certain that everyone is using the same container that works in the same way.

The container then becomes the distribution and testing environment for the application, and when it’s ready, you can deploy the application into your production environment either as a container or an orchestrated service. 

Docker offers the following advantages:

Agile application development: Docker accelerates the development life cycle by providing standardized environments in which developers can work via local containers that are great for continuous integration and continuous delivery (CI/CD) workflows. 

Docker containers are also very portable and can run on laptops, in data centers, in the cloud, or in hybrid environments. This agility and portability streamline and simplify workload management for developers, letting them scale up or tear down applications and services in near real time and according to their business needs. 

Better TCO: Since Docker lets you run more workloads on the same hardware, it saves you money and provides a much better total cost of ownership (TCO) than traditional application development. Using Docker, you can take advantage of your full compute capacity. 

Advantages of Kubernetes

Kubernetes is an orchestration platform that streamlines the tasks of managing Docker containers. 

Specific Kubernetes advantages include:

Flexibility and portability: Kubernetes is highly portable because, unlike most other orchestration platforms, it can be used on many different infrastructure and environment configurations. Kubernetes works with almost any type of container runtime and any type of infrastructure, whether it’s public cloud, private cloud, or an on-premises server, as long as the host operating system uses a version of Linux or Windows (2016 or newer). Kubernetes can also host workloads running on a single cloud and workloads spread across multiple clouds. It can also easily scale from one cloud to another.

Enhanced developer agility: Kubernetes lets developer teams use GitOps, a set of practices to manage infrastructure and application configurations using Git, an open source version control system, to much more rapidly scale and deploy the code used in their applications. 

Proven market leader: While this wasn’t necessarily true five years ago, IT teams across the globe, and in many different industries, now use Kubernetes on a daily basis. Since most developers and IT engineers are familiar with Kubernetes, it makes it much easier for businesses to adopt it. The learning curve is nowhere near as steep as that of other application-building technologies. 

How Kubernetes Works with Docker

Kubernetes previously used an internal component called “dockershim” to interface with Docker. As of version 1.24, dockershim has been deprecated and removed, meaning Docker Engine is no longer supported as a runtime.

However, Kubernetes still supports Docker-built container images because modern runtimes like containerd and CRI-O follow the same OCI image standard. Today, most Kubernetes users build containers using Docker CLI tools but run those containers using a CRI-compliant runtime like containerd.

Portworx: Modern Storage for Kubernetes Workloads

As Kubernetes has evolved into the industry-standard platform for deploying containerized applications, so has the need for storage that’s just as dynamic, scalable, and cloud-native. That’s where Portworx® comes in.

Portworx is a Kubernetes-native data management platform purpose-built for modern, stateful applications. It enables organizations to run mission-critical databases, analytics, AI/ML pipelines, and enterprise applications in containers—across any cloud or on-prem environment—with production-grade storage, availability, and data protection.

With Portworx, you get:

• Persistent storage for Kubernetes: Scale volumes up or down automatically with container demands, across block, file, or object storage backends.
  
• High availability and disaster recovery: Replicate volumes across nodes, racks, or clouds with zero downtime and zero data loss.
  
• Integrated backup and restore: Protect your containerized workloads with application-aware backup policies and point-in-time recovery.
  
• Automated provisioning and scaling: Portworx StorageClass policies integrate natively with Kubernetes to automate volume provisioning, resizing, and migration.
  
• Multi-cloud and hybrid support: Run consistent storage and data services across AWS, Azure, Google Cloud, and on-prem environments.

Portworx integrates deeply with the Kubernetes ecosystem and supports modern CRI-based runtimes like containerd and CRI-O, making it the ideal data platform for today’s production Kubernetes environments.

By adopting Portworx, you gain the flexibility, resilience, and performance needed to manage stateful applications in containers—no matter where they run.rtworx, you gain the flexibility, resilience, and performance needed to manage stateful applications in containers—no matter where they run.