Amazon Echo is a 9.25-inch-tall cylinder speaker with a 7-piece microphone array. It responds to the wake word "Alexa" and is capable of voice interaction, controlling compatible smarthome devices, music playback from smart devices over Bluetooth, making to-do lists, setting alarms, streaming podcasts, playing audiobooks, reading PDFs, providing weather forecasts, warning you of traffic conditions, answering trivia, and supplying other types of information in real-time.

Echo requires a Wi-Fi connection in order to respond to voice commands and fetch content for you, and it must remain plugged in for power.

Echo Dot is 1.6-inch-tall cylinder with one tiny speaker. It's basically just the top section of Amazon Echo - and half the price, but equally as smart. It supports always-on Alexa, connects to the cloud to stream music, controls your smarthome devices, and does all the same stuff as Echo. The original Echo Dot launched in the US in March 2016, but it was refreshed when Amazon announced its UK release.

The main difference between Dot and Echo is that the full-size speaker is gone. The idea is you'll hook Dot up to your own audio setup (via out jack or Bluetooth), so you can use Alexa with your existing speakers. That tiny speaker won't output much audio; it's only for Alexa voice feedback (which, again, requires Wi-Fi).