Application settings properties have a scope that is based either at the application or the user level. As the categories imply, application-scoped settings properties present uniform values to all users of the application, whereas user-scoped properties have dedicated values for each user of the application.

The System.Configuration.ApplicationScopedSettingAttribute indicates that a property should be considered an application-level setting, and that appropriate storage decisions should be made accordingly by the settings provider.

A scope attribute is required for each settings property. If a property is not applied with either a System.Configuration.ApplicationScopedSettingAttribute or System.Configuration.UserScopedSettingAttribute, the property is not recognized by the settings provider—it is not serialized. It is invalid, however, to apply both attributes to the same property. Such an attempt will cause a System.Configuration.ConfigurationErrorsException to be thrown.