Amazon has just introduced its new lineup of tablets, aiming to build on the success of its tablets despite flopping on the smartphone market.

Not too long ago, the company tried its luck on the highly-competitive smartphone market with its Fire Phone, but failed to see much success. In fact, Amazon and AT&T, the exclusive carrier for the device, dropped the price of the Fire Phone to just 99 cents just months after release.

On the other hand, Amazon's tablets have always been pretty popular, and the company is now building on that success with the latest generation of Kindle Fire devices. Amazon has now unveiled two refreshed tablets, as well as four new ones, that are ready to join the Kindle Fire family.

Kindle Fire HDX 8.9

The new Kindle Fire HDX 8.9 is a refreshed version of last year's model, which launched around this time in 2013 with a quad-core Qualcomm Snapdragon 800 processor and 2GB of RAM under the hood. The refreshed model now comes with a more powerful Snapdragon 805 processor, which boasts a 70 percent faster graphics performance while still delivering roughly 12 hours of battery life.

The new iteration also brings improvements in the connectivity department, now sporting the speedier Wi-Fi 802.11ac standard instead of the 802.11n found on its predecessor. Other improvements include Dolby Atmos surround technology, as well as a new "Dynamic Light Control" mode that should make the pages of a book look more like a piece of paper by tweaking the light balance settings in different lighting conditions.

Otherwise, all other features remain the same, including the 8.9-inch display with a resolution of 2,560 x 1,600 pixels. The new Kindle Fire HDX 8.9 comes with a $379 price tag and will be ready to ship in October, but interested customers can already pre-order it from Amazon's website. The company is also offering a Bluetooth keyboard accessory priced at $59.99, which it claims is the "thinnest and lightest full-featured keyboard with a trackpad." For more details, check out the Amazon's press release at this link.

Kindle Fire HD

The Kindle Fire HDX 7 remains unchanged in terms of hardware and now costs $199, marking a $30 price cut, but the company has now launched a brand new Kindle Fire HD series. The two new tablets in the lineup come with either 6- or 7-inch displays, but otherwise share the same specifications.

The new Kindle Fire HD slates come with 720p displays, 1.5GHz quad-core processors, front- and rear-facing cameras, and Dolby Digital Plus Audio. The two models will be available in black, white, cobalt, magenta, and a yellowish-green color called citron. The 6-inch Kindle Fire HD costs $99, while the 7-inch model costs $139. For more details, check out Amazon's announcement at this link.

Kindle Fire HD Kids Edition

Amazon has also introduced a "Kids Edition" of both new Kindle Fire HD models, specifically designed with children in mind. The slates come with a rubber case to make them more durable, and they also come with a two-year "worry-free" guarantee to replace a damaged or broken tablet. Moreover, Amazon is also throwing in a one-year subscription to Amazon FreeTime. The 6-inch Kindle Fire HD Kids Edition costs $149, while the 7-inch model costs $189. Head here for more details.

Fire OS 4

It's worth pointing out that all of these newly-announced tablets com with Fire OS 4 on board, codenamed "Sangria," which is based on Android 4.4 KitKat. Fire OS 4 aims to deliver a more refined user interface (UI) with quick access to media content, as well as individual user profiles so that each family member "can have their own individual email, Facebook and Twitter accounts, settings such as display brightness, bookmarks, spot in a movie, and game levels."

Older models will also benefit from the new Fire OS 4, as Amazon announced that an over-the-air update will hit all third-generation Kindle Fire tablets, as well as the Fire Phone, in early 2015.

Lastly, Amazon also introduced new e-readers, and you can find out more about them from the company's press release at this link.