If you put a clip from an event in the timeline then it belongs together. You can check that when you right click on the clip and choose Reveal in Finder (Shift+Cmd+R)
If you put a clip or audio file in your timeline that's not in the event. Than it is automatically copied to your event. You can see that in the browser but also in the Finder. Events -> Project Name -> Original Media
Thanks for answering, I see what you mean but this is not my point.
I'm not talking about the clip media, that is indeed shared between clips in the Events Library and in the timeline.
I refer to a feature in Final Cut Express and Pro (up to 7) where some clip properties are shared between a "master" clip and all its "affiliates", for example its name (while other "unique" properties are specific of a clip instance: e.g. in and out points). Only if you explicitly make a clip independent, then its link with its master is broken.
To see what I mean in FCP X first drag a clip from the Events Library into the timeline, then rename the clip in the Events Library with a more meaningful name: its "copy" in the timeline keeps its old name...
If you do the same in FCE, the clip copy in the timeline has its name changed as well.
OK probably this is not one of the most important features in FCP, but I think it was useful, and was also related to the way clip reconnection worked (reconnecting the master clip reconnected all its affiliates, while independent clip needed separated reconnection... but this is another story)
They don't have the same relationship Piero because of the way the application's built. It's why some functions like match frame are not included. One problem is the events are not specific to a single project. So if I changed a clip name in one project, it would change the clip name in the event browser, and then also in every other project that uses the clip.