FEATURE STATE: Kubernetes v1.18 [beta]  When you run a Pod on a Node, the Pod itself takes an amount of system resources. These resources are additional to the resources needed to run the container(s) inside the Pod. Pod Overhead is a feature for accounting for the resources consumed by the Pod infrastructure on top of the container requests & limits.
In Kubernetes, the Pod's overhead is set at admission time according to the overhead associated with the Pod's RuntimeClass.