Restore without root

[starbrights]

No really file a bug, it is a question here - and don't know where else to ask:

Can I restore app and even more important data of app without having root, but maybe with adb?
Think app is always base.apk and can be installed without problem, but what about data? Is it somehow possible with adb? If so, how?
Data are saved in zip. Guess cache is often not used, but what about other data?