When Amazon.com (AMZN -2.99%) unveiled its fourth generation of Fire tablets last week, it seemed to include a little something for everyone. Amazon hailed the new Fire HD, for example, as "the most powerful tablet under $100" -- the 6-inch version starts at just $99 -- which seems fair considering its 1.5 GHz processor has three times the graphics performance of the much more expensive Samsung Tab 4.

Then there's the Fire HD Kids Edition, which represents an intriguing alternative to existing children's tablets given its own powerful processor; parental controls and content with a free year of FreeTime Unlimited; and even a two-year, no-questions-asked replacement guarantee if the tablet is broken.  

Finally, the higher-end Fire HDX is a solid upgrade from its predecessor, equipped with a 2.5 GHz processor, 70% faster graphics engine, and a vivid 8.9-inch display with more than 4 million pixels and 100% sRGB color accuracy -- all with a 20% lighter design than an iPad Air for just $379.

But perhaps most important is one thing these tablets will all share: a new Android-based operating system dubbed Fire OS 4 "Sangria." Amazon said Fire OS 4 contains "hundreds of platform updates and exclusive new features." Here are three things, then, both investors and consumers need to know about the new operating system

Fire OS 4 is delightfully predictive
First, Fire OS 4 draws on predictive behavioral features already incorporated into other Amazon products. Advanced streaming and prediction, for instance, was introduced in Amazon's popular Fire TV device in April, and aims to predictively buffer the movies and TV episodes you're most likely to watch next. If it guesses correctly, the tablet can start the video instantly when you do choose to watch it. 

In addition, through its new smart suspend functionality, Fire OS 4 develops a device-specific profile for when each tablet is typically not in use, and proactively turns the wireless off and on to save power.

Fire OS 4 is deeply integrated into the cloud
Next, Fire OS sports heavy integration with the Amazon cloud with the aim of improving both processing power and ease of use.

To start, Amazon is giving users free unlimited storage in Cloud Drive for photos taken on Fire devices -- a great thing if you find your photos suck up a huge amount of your device's storage. Amazon is also including a new "Family Library" feature to allow households to synchronize apps, games, books, Prime Instant Video, and other content between various Amazon accounts and devices. The company knows families share their Prime memberships and digital purchases, anyway, so it's officially embracing the practice -- and gaining untold rapport with customers in the process.

Finally, beginning with the Fire HDX 8.9, Amazon is using Fire OS 4 to broaden the scope of Firefly, which first appeared on the Fire Phone earlier this year and allows users to scan and recognize more than 100 million real-world items. That includes phone numbers, paintings, audio from movies or music, books, grocery items, and virtually any other product you can think of. If you still can't visualize what that means, here's a quick clip from Amazon CEO Jeff Bezos' introduction of Firefly in June:

Of course, the massive computing and storage requirements to perform such object recognition in a timely manner can't be contained in a mobile device (yet), so Amazon cleverly passes each request through its powerful servers in the cloud.

Fire OS 4 comes with (lucrative) ulterior motives
Particularly given the inclusion of Firefly, it's evident the company has ulterior motives for Fire OS 4: namely, to bolster Amazon's position as the world's 800-pound gorilla of online retail. Firefly not only allows users to recognize millions of real-world items, but also enables them to take quick action by chasing those items directly from Amazon. If those users are also Prime customers who enjoy free two-day shipping for many items, the process becomes ridiculously convenient.

Of course, Amazon also needs to be careful here. On one hand, tablet consumers could be put off by what they view as Amazon's self-serving efforts to bolster retail product sales through their own hardware devices. On the other hand, many consumers are using such mobile devices as shopping companions, anyway, so it makes sense for Amazon to use its tablets to simplify the task.

What's more, supplemental features such as predictive streaming and unlimited Amazon cloud photo storage serve as icing on the cake. It should come as no surprise, then, that Fire OS 4 will also be made available for both the Fire Phone and all third-generation Fire tablets via a free over-the-air software update.

In the end, Amazon bringing all these features together in millions of devices with Fire OS 4 convinces me it's only a matter of time before the company ensures its growing ecosystem of products becomes indispensable to everyday consumers.