The Kindle e-reader was introduced by Amazon.com in 2007 and it quickly became a success. In fact, by July 2010, Amazon.com CEO Jeff Bezos announced that Kindle e-books were outselling traditional hardcover books. Since its initial release, the Kindle has undergone a number of changes, but the purpose remains the same: the Kindle is an e-reader that can hold thousands of books in a digital format smaller than a single hardcover book.
First generation Kindle
The first generation Kindle, sometimes called the Kindle 1, went on sale in 2007. It has a 6-inch diagonal screen and measures 7.5 inches high, 5.3 inches wide and 0.7 inches thick. The device weighs 292 grams and can hold about 200 non-illustrated e-books in its 256 megabytes of memory. An SD card slot allows for memory expansion up to 4GB, which can hold about 3,500 non-illustrated books.
The first generation Kindle can access the Kindle store and Wikipedia through its EVDO, high-speed network connection, but is not equipped for Web browsing. If the wireless connection is left on continuously, the Kindle 1 will need recharging every other day. If the wireless connection is turned off, the Kindle 1 can go for about a week without recharging.
Second generation Kindle
The second generation Kindle, also known as the Kindle 2, went on sale in 2009. The Kindle 2 has a 6-inch display screen and is 8 inches tall, 5.3 inches wide and 0.36 inches thick. Although taller than the Kindle 1, this second-generation device weighs slightly less at 289 grams. Its 2GB of internal memory can store more than 1,500 non-illustrated e-books. The Kindle 2 does not have memory expansion capability. It can work for about four days when wireless is left on and for up to two weeks if the wireless is turned off.
The Kindle 2 features WiFi access and allows access to a simple Web browser. Other features added to this model include a "Read to Me" feature, the ability to download music and podcasts to the Kindle and PDF document conversion.
The Kindle DX, a larger Kindle, was released in 2010. The DX measures 10.4 inches tall, 7.2 inches wide, and 0.38 inches thick. The diagonal display measures 9.7 inches, noticeably larger than its predecessors are. The larger size is accompanied by more heft -- the Kindle DX weighs 535 grams. It offers 4GB of internal memory, sufficient to store over 3,500 non-illustrated books. The DX does not have expansion capability.
The Kindle DX has built-in 3G wireless coverage that works in 100 different countries and territories, Amazon.com reports. The DX offers a simple Web browser, the "Read to Me" feature and MP3 playback. With wireless turned on, the Kindle DX will retain power for about one week. With wireless switched off, the DX can go two or three weeks without needing recharging.
Third generation Kindle
The third generation Kindle, often called Kindle 3, was introduced in 2010. This Kindle featured the same 6-inch display screen as the Kindle 1 and 2 but became the lightest Kindle yet at 246 grams. It measures 7.5 inches tall, 4.8 inches wide and 0.335 inches thick. It has 4 GB of internal memory and offers the same storage capacity as the Kindle DX -- about 3,500 non-illustrated books. The Kindle 3 does not have an SD slot for memory expansion.
The Kindle 3 comes in two versions, one with 3G wireless and one without. The 3G wireless model can access the Web from virtually anywhere, while the other requires a WiFi hot spot for Internet access. The Kindle 3 has a simple Web browser, the "Read to Me" feature and MP3 playback. With wireless switched off, the Kindle 3 can go about a month without recharging. With wireless enabled, it can go about 10 days.