What is etcd-0 on my Kubernetes cluster?

Hi,

When I run kubectl get cs I see etcd-0 running. Is this etcd the shared k/v store or is it something else? I ask because even though I see the service I don’t see any indication that I can interact with it.

➜  ~ kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-0               Healthy   {"health":"true"}