In case we have no idea before hand about how much resources - CPU, RAM - an application running inside pods would need, we could set default resource limits and resource requests for our pods using the kubernetes object "LimitRange".
Below is an example of a LimitRange object:
The resource requests is what the pod gets when it starts. If the pod needs more resources, it can't get more than what is set in the resource limits.
The LimitRange object can help us set default resources for a whole namespace if we "apply" that limit to a namespace using the below command:
If we don't mention a particular namespace, the limit will apply to the default namespace and the pods that don't explicitly define resource limits and resource requests, will use the default ones.