KINDLE is an ebook system created by AMAZON, and within this system, books are available to download (some free and some pay) from the Amazon web site. However, the item which is being advertised on TV is the KINDLE READER, which is available in a couple of versions, WiFi only and WiFi & 3G.
It works like this:
You login into your Amazon account and buy a ebook (or 'buy' a free book for £0), the book is then added to your library.
Once in your library (on Amazon's Server), you can download to your 'reader'
This can be either the KINDLE READER (or DEVICE), or to any of the free applications which can sit on your other 'devices' , like your PC, MAC, Smartphone (Android, iPhone) or Android Tablet or iPAD. The Android and Apples devices also have their own ebook systems, (ibooks or Aldiko Books) which yo can subscribe to and use if you like, but once you have a KINDLE Account...any device will do. Once purchased, you can download to more than one device.
So you do not have to wait to buy a KINDLE Device to take advantage of the KINDLE System. Although the Kindle reader is a great holiday / travel device, nice and light, low power usage, but this is because there is no backlight so just like a normal book a light to read by is needed.
I have downloaded both novels and technical manuals to my Kindle and found that reading a novel is a good experience, but trying to use it as a technical manual is not as good and a traditional paper version would be better.
There is a new Kindle Reader Device for sale now, it is a smaller version without the 3G and a keyboard, and is cheaper, well worth the money.