This will show basic information about the instances that have been registered with the registry. Since we have only booted up the gateway service, we will see only one instance here. Basically, this will list all the instances that are connected to this registry service.
It shows the status of the system, the name of the system, and then the instance ID. The instance ID is generated based on the configuration in the application.yml of JHipster Registry. It assigns a random value.