Traefik weighted/services/0/name use for what?

Traefik Traefik v2 (latest)
1

who konw
traefik/tcp/services/<service_name>/weighted/services/0/name
what this name use for？
is it Write casually？

2

https://docs.traefik.io/v2.2/routing/services/#weighted-round-robin-service

3

thank you very much.................