The ability to restrict certain types of incoming or outgoing calls on devices operating with the Android operating system is a security and management feature available to users. For instance, a user may choose to block all international outgoing calls to prevent unintended charges, or block all incoming calls from withheld numbers.
This functionality provides considerable control over communication expenses and can enhance personal security by mitigating unwanted or potentially harmful contact. Historically, such features were primarily managed by network providers; however, modern mobile operating systems integrate these controls directly into the device settings, empowering users to manage their call access.