What does synchronisation mean? What data is being synchronised?

Question

On my 80GB IpoD classic I replace music several times. After successful transfer of imported CDs from the mediathek onto the Ipod I finally clean up the mediathek; that means:
Mediathek and IpoD can never be synchron because of a clompletely different contents. (I manually administer my IpoD)
Synchron to me means: 2 or more different parts do exactly the same thing.
my question:
What does synchronsation mean in this context? What info has to be synchronized between Ipod and mediathek?
Thanks for answering

Answer 1

You are correct that the common meaning of synchronise is to make two things the same. iTunes uses this term slightly loosely but if you set your device to sync with selections from your iTunes library, e.g, certain playlists, podcasts, TV shows etc. then changes in those part of your library can be automatically reflected on the device. For iTunes syncronisation is one way - from iTunes to the device - although it can also transfer purchased items from the device back to iTunes. When automatically syncing it can also update play counts & last played dates both from iTunes to the device and from the device to iTunes.
If you manually manage your iPod then it will still have data that needs to be copied to it or deleted at some point. Whenever data is being modified on the device it will display the "syncronising" screen.
tt2