A pod is the unit of work in Kubernetes. Each pod contains one or more containers. Pods are always scheduled together (that is, they always run on the same machine). All the containers in a pod have the same IP address and port space; they can communicate using localhost or standard interprocess communication. In addition, all the containers in a pod can have access to shared local storage on the node hosting the pod. The shared storage can be mounted on each container. Pods are an important feature of Kubernetes. It is possible to run multiple applications inside a single Docker container by having something such as supervisord as the main Docker application that runs multiple processes, but this practice is often frowned upon for the following reasons:

• Transparency: Making the containers within the pod visible to the infrastructure enables the infrastructure to provide services to those containers, such as process management and resource monitoring. This facilitates a number of convenient functionalities for users.
• Decoupling software dependencies: The individual containers may be versioned, rebuilt, and redeployed independently. Kubernetes may even support live updates of individual containers someday.
• Ease of use: Users don't need to run their own process managers, worry about signal and exit-code propagation, and so on.
• Efficiency: Because the infrastructure takes on more responsibility, containers can be more lightweight.

Pods provide a great solution for managing groups of closely related containers that depend on each other and need to cooperate on the same host to accomplish their purpose. It's important to remember that pods are considered ephemeral, throwaway entities that can be discarded and replaced at will. Any pod storage is destroyed with its pod. Each pod gets a unique ID (UID), so you can still distinguish between them if necessary.