Kubernetes Container Terminologies

This guide is intended for users who have basic understanding of containers and container terminologies. This document expects the users to be familiar with the following container terminologies that are used in this guide:

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Node: A node is a working machine in Kubernetes cluster. They are working units which can be physical, VM, or a cloud instance.

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Cluster: A group of nodes.

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Image: Containers are launched from these images (similar to images in cloud environments).

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Pod: A pod is a collection of containers and its storage inside a node of Kubernetes cluster. It is possible to create a pod with multiple containers inside it.

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Service: A service is a logical set of pods. It can be defined as an abstraction on the top of the pod which provides a single IP address and DNS name by which pods can be accessed.

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Namespace: Provides an additional qualification to a resource name. This is helpful when multiple teams are using the same cluster and there is a potential of name collision.

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Replication controller: Responsible for managing the pod life cycle.

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DaemonSet: A DaemonSet ensures that all (or some) nodes run a copy of a pod. As nodes are added to the cluster, pods are added to them. As nodes are removed from the cluster, those pods are garbage collected. Deleting a DaemonSet will clean up the pods it created.

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Job: Main function of a job is to create one or more pod and tracks about the success of pods.

For a detailed list of terms and definitions, refer to the Kubernetes Glossary: https://kubernetes.io/docs/reference/glossary/?fundamental=true