APK is a short form stands for Android Packaging Key. It is a compressed key with classes, UI’s, supportive assets and manifest. All files are compressed to a single file is called APK.

An APK (Android Package) file is the file format used for distributing and installing applications on Android devices. It contains all the elements needed for an app to be installed on a device, including the app’s code, resources, manifest file, certificates, and sometimes additional files like assets. APK files are the package format used by the Android operating system for the distribution and installation of mobile applications. Users can typically install an APK file by downloading it from the internet or other sources and then manually initiating the installation process on their Android device.