Permission concept in Android

Android contains a permission system and predefines permissions for certain tasks. Every application can request required permissions and also define new permissions. For example an application may declare that it requires access to the Internet.

Permissions have different levels. Some permissions are automatically granted by the Android system, some are automatically rejected. In most cases the requested permissions are presented to the user before the installation of the application. The user needs to decide if these permissions are given to the application.

If the user denies a required permission, the related application cannot be installed. The check of the permission is only performed during installation, permissions cannot be denied or granted after the installation.

An Android application declares its required permissions in its AndroidManifest.xml configuration file. It can also define additional permissions which it can use to restrict access to certain components.