Is K8s Service component running on both node? or is controlled by K8s controller?

When I studying K8s tutorial:

the Pod replications connect to the same Service.

I have a question about it,
is the Service only one running on one of nodes? or have several replications too?

Services are available from all nodes, but they don’t really “run”. They aren’t a program, but a set of rules (iptables, ebpf, etc).

please explain more, how it works.