Answer 2: Enamel is the hard material that coats your teeth, and is made mostly of a mineral. However, we call other things enamel. There's enamel paint, which is totally different, and there's also porcelain enamel, which is used to make a lot of dishes.
All of this is due to Amazon's unique approach with the Echo. It's not a portable speaker like we've seen from Jambox and Logitech. Instead, it's a rather large, cylindrical device that needs to be plugged into power. It's something you'll likely just leave in a single spot in your home.
A line interactive UPS directs main utility power to your equipment as long as it's available. This power is routed through a buck-boost transformer which corrects high or low voltage within a limited range. When the utility power fails this type of UPS switches to the battery as a source of temporary power.