Once you have begun to develop an app, it’s important to test it on the appropriate device targets. The emulator can be used in conjunction with AVDs to simulate device targets. That said, testing on real physical devices is essential for complete test coverage. The emulator, while powerful, cannot emulate the idiosyncrasies of individual devices. Therefore, a solid test plan must incorporate both emulators and real devices. After all, your users won’t be running your app on an emulator, will they?