It can be used to read ebooks. Right now the Amazon Kindle and Sony Reader are the most popular ebook readers, but the Kindle is having a bigger market share because it is better than the Sony.

May be you can read this article to get more idea about the Kindle ebook reader:

http://ezinearticles.com/?How-Does-the-Kindle-2-Work?&id=2003315

There is also a great review here from a top reviewer, telling about all the benefits of the Kindle:

http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2Freview%2FR9J54TZ1541OR%3Fie%3DUTF8%26ref%255F%3Dcm%255Fcr%255Frdp%255Fperm&tag=more_info-20&linkCode=ur2&camp=1789&creative=390957

You’ll have a much better idea about them after reading these. Hope this helps.