Kubernetes objects are the entries in the cluster, which are stored in etcd. They represent the desired state of your cluster. When we create an object, we send the request to the API server by kubectl or a RESTful API. The API server will check whether the request is valid, store the state in etcd, and interact with other master components to ensure the object exists. Kubernetes uses namespaces to isolate the objects virtually, so we could create different namespaces for different teams, usages, projects, or environments. Every object has its own name and unique ID. Kubernetes also supports labels and annotations to let us tag our objects. Labels in particular can be used to group the objects together.