Rapport

Rapport is a framework that provides information about devices that share an iCloud account. This also includes family members as well as "guests" such as those who are using media services such as AirPlay. This breaks down broadly into the UI seen in System Preferences where a user's devices are shown.

Not to be confused with IBM Trusteer Rapport, which includes an identically-named but otherwise entirely different  launch daemon.

Rapport.framework
This framework allows a client to ask for other signed-in devices to an iCloud account.

RapportUI.framework
This provides UI elements about devices including their icons and identifiers

Services
Devices implement services to respond to remote requests via the  service