There are three new resolution classes according to Android Dev Blog;
Since any given device falls within above three classes, it will be easier for developers to tailor their applications to adapt to the the devices. Android Developper has only to utilize the new tools that have been introduced into Android Framework APIs and SDK. They are also described well in the documentation at the developer site The documentation also provides the developer with a quick check list to verify if the developers app will run on an Android device of any screen size.
- small: devices with a screen size smaller than the T-Mobile G1 or Samsung I7500, for example the recently announced HTC Tattoo
- normal: devices with a screen size roughly the same as the G1 or I7500.
- large: devices with a screen size larger than the G1 or I7500 (such as a tablet-style device.)
Support for additional screen resolutions and densities in Android