logger.factory:
    class: Drupal\Core\Logger\LoggerChannelFactory
    arguments: ['@request_stack', '@current_user']
    tags:
      - { name: service_collector, tag: logger, call: addLogger }

以上代码的定义中name是说这个服务会进行服务收集. 收集的服务名为 logger.  收集的服务将会调用Drupal\Core\Logger\LoggerChannelFactory::addLogger这个函数

https://www.drupal.org/docs/drupal-apis/services-and-dependency-injection/service-tags