The Post's Hayley Tsukayama reviews Amazon's new Kindle HDX. ( founder and chief executive Jeffrey Bezos is the owner of The Washington Post.) (Sandi Moynihan/Sandi Moynihan and Hayley Tsukayama/The Washington Post)

Well, that was quick. Just a day after Apple announced its newest full-sized tablet, the iPad Air, Amazon rolled out a new banner ad on its homepage proclaiming the Kindle Fire HDX is “lighter than Air.”

And it is true — both of the latest models of the Kindle Fire are lighter than their Apple competitors: The larger model of the Kindle Fire HDX weighs 0.82 pounds to the iPad Air’s weight of 1 pound. And the smaller Fire is 0.66 pounds to the new iPad mini with retina display’s 0.73 pounds.

But it’s also worth noting that it’s not a straight comparison.

For one, the screens on both Kindle Fire HDX models are smaller than on their corresponding iPads. The larger Kindle Fire HDX is 8.9 inches to the iPad Air’s 9.7, which retains the screen size of the standard iPad. The smaller Kindle Fire is 7 inches to the iPad mini‘s 7.9 inches.

The construction of the two devices is also different. The iPads are made with aluminum bodies to preserve Apple’s premium design philosophy, while the Kindle Fire HDX models show Amazon’s low-price philosophy with plastic bodies. Amazon has improved the feel of its tablets with this latest model. But it’s still pretty clear that its design has a different goal: to be made inexpensively to keep prices low.

Still, the quick turnaround on the ad — and the fact that it calls the iPad Air out by name — shows that it’s going to be a particularly fierce holiday season in the tablet market, as Amazon and Apple duke it out with Microsoft, Nokia, and Google for a place in gift-wrapped boxes across the world.

In the United States, as Bloomberg reported last month, Amazon had a 4.6 percent share of the market ahead of its HDX launch, as compared to Apple’s 50.7 percent. But the online retailer has been pushing its tablet hard and improving core features such as browsing and typing as well as introducing a new 24/7 customer service feature. That’s a calculated move to go after first-time tablet owners and for those looking for something cheap that serves their basic needs.

(Amazon chief executive Jeff Bezos is the owner of The Washington Post.)