Containerization has transformed software development and deployment by enabling efficient packaging, shipping, and execution of applications. Containers are self-contained units that encapsulate applications and their dependencies, providing a lightweight, isolated runtime environment. This ensures portability and consistency across platforms, addressing the “it works on my machine” problem. Containerization supports DevOps practices, enabling Continuous Integration and Delivery (CI/CD) and promoting modular microservices architecture (Sarishma & Abhishek, 2021, p. 48).

Docker is the leading open platform for developing, shipping, and running applications in containers. It simplifies building, deploying, and managing containers, which are standardized executable components combining application code with OS libraries and dependencies. Docker separates applications from infrastructure, enabling fast software delivery and consistent environments from development to production (Docker, 2025).

The core of Docker is the container – a loosely isolated, lightweight environment that packages an application with everything needed to run it, independent of the host system. This makes containers ideal for CI/CD workflows. Docker uses a client-server architecture: the Docker client communicates with the Docker daemon (dockerd), which manages objects like images and containers. Containers are runnable instances of images – read-only templates with instructions. Docker Registries, like Docker Hub, store and distribute these images. Containers are lighter than VMs, sharing the host OS kernel, resulting in faster startup times and greater efficiency for running multiple application instances on the same hardware. Docker images are built using Dockerfiles – text files with instructions – and are comprised of layers for versioning and reuse (Susnjara & Smalley, 2025).

Kubernetes (K8s), an open-source platform open-sourced by Google, manages containerized workloads and services with declarative configuration and automation. It provides scalability, self-healing (restarting failed containers), automated rollouts and rollbacks, service discovery, load balancing, and storage orchestration, ensuring no downtime and driving the system toward the desired state. Kubernetes is essential for resilient production environments (Kubernetes, 2024).

Cloud native stacks utilize Containers-as-a-Service (CaaS) and Functions-as-a-Service (FaaS). CaaS enables orchestration and management of containers and clusters, providing platform-agnostic builds, enhanced portability, and reduced costs. FaaS allows code execution in response to events without managing underlying servers, charging only for resources used. The cloud native lifecycle – Develop, Distribute, Deploy, and Runtime – requires integrated security (Shift Left). Security practices include early threat modeling and vulnerability scanning (Develop), image scanning and artifact signing (Distribute), and orchestration systems with least privilege policies and self-healing during Deploy and Runtime phases (Krieger et al., 2022, p. 13).

References:

1. Docker. (2024). What is Docker? Docker Documentation. Retrieved from https://docs.docker.com/get-started/docker-overview/
2. Sarishma, & Abhishek. (2021). A systematic review of the impact of containerization on software development and deployment practices. Computology: Journal of Applied Computer Science and Intelligent Technologies, 1(1), 40–51.
3. Kubernetes. (2024). Why you need Kubernetes and what it can do. Kubernetes Documentation. Retrieved from https://kubernetes.io/docs/concepts/overview/#why-you-need-kubernetes-and-what-can-it-do
4. Krieger, B., Kennedy, C., Değirmenci, F., Kautz, F., Bork, J., Moore, M., Pruchniak, M., Joglekar, P., Faisal, R., & Raghunathan, S., et al. (2022). Cloud native security whitepaper version 2 (pp. 9–25). Cloud Native Computing Foundation.
5. Susnjara, S., & Smalley, I. (2025). What is Docker? IBM Think. Retrieved from https://www.ibm.com/think/topics/docker