Amazon Echo is a smart hardware system. Amazon has used an artificial intelligence engine in Amazon Echo to enable interaction with users. This program is called Alexa. We can perform tasks on Amazon Echo through voice commands. There are some keywords that are used by Alexa to identify and recognize voice commands. Currently, we can buy Amazon Echo from https://www.amazon.com/dp/B00X4WHP5E/. You can see Amazon Echo here:

Amazon also provides a cheap hardware device for Amazon Echo, called Amazon Echo Dot (https://www.amazon.com/dp/B01DFKC2SO/). The model's size is small and it is 163 grams in weight. You can see Amazon Echo here:

To start communicating with Amazon Echo, we should say Alexa. This is a keyword using which Amazon Echo starts to listen to commands. After recording the commands, Amazon Echo will interpret these commands to perform something.