Docker is a containerization platform, used for building container images including everything needed to run an application – the application code, binaries, scripts, dependencies, configuration, environment variables, and so on.
Kubernetes is a container orchestrator, used for automating manual processes involved in deploying, managing, and scaling containerized applications.
Kubernetes runs across a cluster while Docker runs on a single node. Also, Kubernetes is more extensive than Docker and it further coordinates node clusters in production at scale.