Within a Kubernetes Cluster, every pod can reach every other pod
–> POD Networking Solution : Internal Virtual Network (Default VxLAN) to which all connect too.
But where does a certain application live. It could have any IP. For this a service is made.
Services are only running in memory and define where a certain application can be found.
Each Worker Node has a kube-proxy process to allow traffic to be forwarded to these Defined Services and checks for new services. This forwarding is done using rules. As an example these could be done using an iptables rule.