Amazon's Echo lineup offers tiered-speaker heights that remind us of Starbucks coffee sizes (grande, venti, and trenta).

The company makes a cylindrical, internet-connected Bluetooth speaker called Echo, which doubles as a personal, cloud-based assistant, addressed as Alexa. It launched in the US in 2015 and it is now coming to Europe and the UK in Autumn 2016.

Alongside Echo, Amazon also offers two sibling speakers that debuted in March 2016 in the US, called Amazon Tap and Echo Dot, the latter of which has now been replaced with a refreshed model that too will be coming to the UK. The Amazon Tap currently isn't available in the UK.

Sit all three speakers next to each other, starting with the Echo and ending with the Dot, and you'd get one tall, one medium, and one short. The differences between Amazon's speakers aren't limited to height though; each one is best suited to a specific environment - whether that be at home, on the go, or as an enhancement to your current audio setup.

Confused about what we mean? No worries. We've dissected how each Amazon speaker is unique and laid out all the details below.

Release date: 2015 in US, 2016 in UK.
Availability: Available in the US (Amazon order page) / Available in UK from 28 September (Amazon UK order page)
Price: $179 / £149
Dimensions: 235 mm x 83.5 mm x 83.5 mm
Weight: 1045 grams
Connectivity: Bluetooth and dual-band, dual-antenna Wi-Fi (MIMO)
Power: Plugs into a wall outlet
Audio: 360-degree sound (2.5 inch woofer and 2.0 inch tweeter)
Alexa: Yes (Always-on/always-listening/voice-activated)

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. Users in the US will see Alexa have an American accent, while UK users will hear a British accent. 

Release date: 31 March 2016 for US
Availability: Available in the US (Amazon order page)
Price: $129.99
Dimensions: 59 mm x 66 mm x 66 mm
Weight: 470 grams
Connectivity: Bluetooth and supports 802.11b, 802.11g, or 802.11n Wi-Fi
Power: Relies on a charging cradle (9 hours of playback)
Audio: 360-degree sound (dual 1.5-inch drivers and dual passive radiators)
Alexa: Yes (Not always-listening; Must touch mic button to access Alexa)

Amazon Tap is a 6.2-inch-tall cylinder speaker with a 7-piece microphone array. So it's a smaller, more portable, more affordable version of Echo, and it comes with full access to Alexa. Unlike the Echo, the Amazon Tap is wireless and must be set into the included cradle in order to charge.

Amazon says it'll stream up to 9 hours of audio on a full charge, or last up to three weeks in standby mode. The Tap isn't an always-on, so you can't say "Alexa" to wake it and instead need to press the microphone button on the front. Other than that, it can do all the same tricks as Echo (so long as you're connected to Wi-Fi).

Release date: September 2016
Availability: Autumn for US and UK (Amazon UK pre-order page)
Price: $49 / £49
Dimensions: 38 mm x 84 mm x 84 mm
Weight: 250 grams
Connectivity: Bluetooth and dual-band, dual-antenna Wi-Fi (MIMO)
Power: Plugs into a wall outlet
Audio: Voice-feedback only (Must be connected to external speakers)
Alexa: Yes (Always-on/always-listening/voice-activated)

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).

The new Echo Dot will be available to buy in a six-pack and 12-pack. For those opting for multiple Echo Dots around their home though, Amazon has introduced a feature that will mean only one Echo Dot, and the closest one, will respond to your request.

Amazon Echo is ideal if you just want to have a stationary Bluetooth speaker that doubles as an always-on, Siri-like personal assistant. It'll provide you with room-filling audio that's sufficient for casual listening but it gets sort of tinny when turned up too much. If you're connected to Wi-Fi, you can ask it all sorts of questions and get it to control your stuff and it is available in the US and will be in the UK before the end of the year.

Amazon Tap is supposed to do all of that, including provide a similar sound experience, but it's ditched the cord and uses a charging cradle in order to be portable. As it's not always plugged into power, always-on Alexa isn't available though. You have to push a mic button to access the service. Tap is therefore useful if you're going to the beach or are always on the go and it is only useful to those in the US.

As for Dot, just think of it as a little, always-on Alexa hub. It's not a speaker but works with your speakers. It will be available in six and 12 packs so you can ensure every room in your home has Alexa listening.