The LoadBalancer service type in Kubernetes exposes the service externally using a cloud provider’s load balancer67. NodePort and ClusterIP services, to which the external load balancer routes, are automatically created

This manifest is used to create a deployment, which is a Kubernetes resource that manages a set of pods with the same configuration. A deployment can also provide declarative updates, scaling, and rolling back for the pods. The created pods are not receiving traffic on port 80, because the manifest does not specify a service or a selector for the deployment. A service is another Kubernetes resource that defines a logical set of pods and a policy to access them. A selector is a label query that matches the pods that belong to the service. Four pods are created as a result of applying this manifest, because the manifest specifies replicas: 4 in the spec section of the deployment

In Kubernetes, all containers within a pod share the same IP address7. A ClusterIP service exposes pods to internal traffic only87. References from Juniper site: IBM, Kubernetes Documentation