On: Amazon Echo Dot

[kayoone]

Alexa probably uses forms of machine learning and also queries lots of services to find the answers you need. Also it learns from every user and gets better for every user this way. That would be really hard to do with an offline device.

[sib → kayoone]

Yes, that is exactly how it works.

If you, as a customer, want to, you can go to Amazon.com and delete all your voice history (or any single interaction).