Answer: Asynchronous communication
Explanation: Asynchronous communication is the sending of the message or information in irregular interval stream.This communication can work without external signal of clock.There is no generation of the synchronized time in the receiver and transmitting clock.This function gives a variable bit rate.
The example mentioned in the question is also an example of asynchronous communication because they don't have simultaneous time shifting property while while using DVR and other devices.
