Containerization

Containerization is the deployment of applications in containers: lightweight, isolated runtime environments that bundle the application code together with all its dependencies and thereby make it run identically everywhere.

Unlike virtual machines, containers do not bring their own operating system but share the kernel of the host – they start in seconds and require significantly fewer resources. The approach was established by Docker; today, open standards (OCI) ensure compatibility between tools. Applications are built as images, distributed in versioned form via registries and operated identically in development, test and production – the basis of modern microservices architectures and CI/CD processes. On the security side, image scanning, minimal base images and controlled registries are among the basic measures.

As soon as many containers are operated across several systems, an orchestration layer is needed for distribution, scaling and resilience – the de facto standard for this is Kubernetes.