Container : Package Software into Standardized Units for Development, Shipment and Deployment.

Docker: Docker is enterprise container plaform which use to create the container and container images.

Docker is a set of platform-as-a-service products that use OS-level virtualization to deliver software in packages called containers. Containers are isolated from one another and bundle their own software, libraries and configuration files; they can communicate with each other through well-defined channels.

There are also some platfrom like docker for example rocket which can be also use to create container images and container.

Kubernetes : Kubernetes is comes under the CNCF organization. Kubernetes called as k8s which is open source project.Kubernetes is orchestration tool which use to handle and manage one or more containers.