What does iTunes really backup? Here's what I think. Is it correct?

[luisadastwin]

iTunes it self does not backup a lot of things...

In fact, the Backup will just contemplate the following:
- iPhone preferences
- App settings
- Bookmarks
- SMS / texting

Contacts will always synch with Outlook / Gmail.
Photos, Apps, Music and videos will synch with what's in iTunes.

So, there's no much left here...

Am I right? Something missing here?

Thanks in advance!