New to Knative

[sanzzz]

HI Everyone,
We are planning to implement knative as it for serverless workloads and cost saving. Would like to understand few things here
Serverless mean - We dont manage servers instead cloud providers will take care of servers. I believe pods are created when there is a request and serve the traffic and scale down to zero - this is handled by knative (acting like a cloud providers in Vm world) . Does it need the kubernetes worker nodes to be always running ? In this case, how does it help with cost saving? Please let me know if am missing something here.

Thanks in advance