ROS Services
Which of the following statements about services are correct?
In ROS terminology, "service" is just another name for "topic"
Services are similar to topics in that they facilitate the passing of messages between nodes.
Services use a request-response message passing scheme, rather than the pub-sub method used with topics.
A request message on a service might actually trigger a new sensor measurement, like a new camera image, with settings like exposure time specified in the message.