Kubernetes have a feature named extended resource. but I do not know the effects of what it brings.
In other words, what are the differences between I use it and I no use it?
Besides, Is the feature similar to the default limit or default request?
Extended resources are custom resources your nodes can advertise to the cluster, to make sure pods scheduled on them are able to have enough of them when scheduling.
The default limit/request allows you to assign these resources implicitly, even if the pod spec did not explicitly specify them.