details of the update process

Could someone describe to me what happens when an android application is updated? Is it the old version uninsta开发者_StackOverflowlled and then installed the new one ? What about the resources the application might need ?

Usually the application itself is removed and user data (like sqlite DBs and preference files) remains on the device. You can check those files on the emulator (or on your phone) by using the adb shell. The data is stored in /data/data/YOUR_PACKAGE/