Many amplifiers now have wireless connectivity via Bluetooth or Wi-Fi to allow music streaming from mobile devices and apps.
Bluetooth: Bluetooth amplifiers works well as a short-range, single zone solution. It is not possible to synchronise music across multiple Bluetooth devices to create a multi-zone system.
Wi-Fi: Wifi amplifiers on the other hand offers greater range and signal stability, as well as better sound quality. Multiple Wi-Fi amplifiers of the same brand can be synchronised together to play in multiple zones at once.