A mod APK, short for modified APK, refers to a modified version of an Android application package (APK). An APK file is the format used to distribute and install applications on Android devices.

Mod APKs are created by modifying the original APK file to add or alter certain features of the application. These modifications can include unlocking premium features, removing advertisements, providing unlimited in-game currency or resources, and making other changes to enhance the user experience.