The main, and most essential, means of communication for any tablet is WiFi. Without having access to WiFi at least some of the time, a tablet will simply not work correctly. The second most common means of communication for tablets is Bluetooth. Bluetooth is not as essential, and rather more uncommon in children’s tablets, but it allows the tablet to communicate wirelessly with other devices, including such as speakers.
The All-New Fire 7 Kids Edition does come with Bluetooth as standard. Whilst not essential, this is a useful extra. The Bluetooth on the Fire comes with “A2DP” or Advanced Audio Distribution Profile, which allows for the wireless transmission of stereo audio from the tablet to compatible devices such as speaker, headphones and microphones.