The relationship between Docker containers and Kubernetes: Docker is a container runtime, Kubernetes is a container orchestration platform. Kubernetes supports multiple container runtimes (Docker, containerd, CRI-O), interacting with runtimes through the CRI (Container Runtime Interface) interface. Docker as a container engine is responsible for creating and managing containers, while Kubernetes is responsible for scheduling, scaling, service discovery, load balancing and other orchestration functions. Kubernetes 1.20+ began deprecating dockershim, recommending using CRI-compliant runtimes like containerd. In practice, Docker is used for local development and testing, while Kubernetes is used for large-scale container management in production environments.