about android emulator diskimage

The emulator provides a default user-data disk image. At startup, the emulator creates the 开发者_开发百科default image as a copy of the system user-data image (user-data.img), described above. The emulator stores the new image with the files of the active AVD.

from:http://androidappdocs.appspot.com/guide/developing/tools/emulator.html

1)What does the default images mean?(userdata.img?)

2)What does the system user-data image mean?(userdata-qemu.img?)

The default images, system.img and userdata.img are copied from the relevant platform folder in your SDK installation.

e.g. these two image files would be copied from $ANDROID_HOME/platforms/android-8/images if you created an Android 2.2 emulator.

The system.img is the /system partition — the OS and pre-installed applications, while the user-data.img includes some non-system applications.