DBUS- Diff of "Service" and "Bus name"

Question

In DBUS programming terminologies, they use Service name interchangebly with Bus name. Or is there a difference?

Answer 1

A "bus" is a "communication world/space". You can have several buses running simultaneously on the same computer: system & session are the traditionnal ones. There can also be private buses. They are usually identified by their daemon socket: "unix:path=/var/run/dbus/system_bus_socket"

A "bus name" is a connection point, it's kind of an identifier. It can be a process connection to a bus. Typically, you address messages to a "bus name". Sometime, that name is "well-known", meaning it has been registered with a another "friendly" name. http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus

A "service" is normally a program that is started on-demand and provide an expected interface (and a a "well-known" "bus name", such as "org.gnome.keyring")

But people often just call "service" a "well-known bus name that provide an interface" regardless of it is launched on-demand or not.

See also http://www.freedesktop.org/wiki/IntroductionToDBus