The [Ability Privilege Level (APL)](accesstoken-overview.md#app-apls) of an application can be **normal**, **system_basic**, or **system_core**. The default APL is **normal**. The [permission types](accesstoken-overview.md#permission-types) include **system_grant** and **user_grant**. For details about the permissions for apps, see the [App Permission List](permission-list.md).
The [Ability Privilege Level (APL)](accesstoken-overview.md#app-apls) of an application can be **normal**, **system_basic**, or **system_core**. The default APL is **normal**. The [permission types](accesstoken-overview.md#permission-types) include **system_grant** and **user_grant**. For details about the permissions for apps, see the [Application Permission List](permission-list.md).
To protect sensitive data and eliminate security threads on core abilities, you can use the permissions in the [App Permission List](permission-list.md) to protect the related API from unauthorized calling. Each time before the API is called, a permission verification is performed to check whether the caller has the required permission.
To protect sensitive data and eliminate security threads on core abilities, you can use the permissions in the [Application Permission List](permission-list.md) to protect the related API from unauthorized calling. Each time before the API is called, a permission verification is performed to check whether the caller has the required permission.
## Available APIs
The table below lists only the API used in this guide. For more information, see [AbilityContext](../reference/apis/js-apis-ability-context.md).
The table below lists only the API used for access permission verification. For more information, see [AbilityContext](../reference/apis/js-apis-ability-context.md).
