What makes a tablet a tablet? (FAQ)

Pop quiz: Which one is the true tablet? Apple iPad, JooJoo, Dell Streak, or HP Slate?

If you guessed any of them you're right. Or you're wrong. Because the answer seems to depend on whom you ask.

The tablet category is heating up lately. IDC expects more than 7 million tablets to ship by the end of the year andmore than 46 million units to ship by 2014. That is in large part due to the success of Apple's iPad, which has flown off store shelves since its introduction in April. Dell, Hewlett-Packard, Asus, Fuijtsu, Acer, Archos, and many others have also flocked to the the decidedly gray area that tablets occupy between a smartphone and notebook.

Perhaps because the category is new, the definition of "tablet" seems sort of up for grabs, depending on who is defining it. Size, features, and specifications are the traditional way of breaking down consumer electronics and PC categories, but the few products currently for sale or coming soon are blurring those lines.

We take a crack at dampening some of the confusion around the latest crop of consumer tablets. (For a complete list of tablets, see the guide put together by CNET's Donald Bell.)

What makes a tablet a tablet?
Traditionally the categories of mobile computing devices break down in terms of size: smartphones have 3- to 5-inch screens, MIDs (mobile Internet devices) range between 5 and 7 inches, and tablets are between 7 and 10 inches.

But the feature set, or what the device can do, is the other half of the equation. According to Gartner, a true tablet is any slate over 5 inches running a full operating system like Windows, Mac OS X, or Linux.

IDC breaks the devices down into media tablets and tablet PCs. A tablet PC has an x86 processor, runs a desktop OS, and has a screen size anywhere from 5 inches to 21 inches. Despite what it may look like, "A tablet PC is a PC," said Richard Shim, IDC analyst. "There's no real limit to them."

These are generally the traditional idea of a tablet, the kind that look like a laptop with a screen that twists that you can close and write on with a stylus, like the Dell Latitude XT or the Asus Eee PC T91.

"A media tablet we're defining as ARM-based, running a smaller OS (non-Windows)," he said. "The screen sizes are between 7 and 12 inches." ARM is a type of low-power processor typically used in mobile devices, whereas x86 processors are used in more robust applications where power consumption isn't as much of an issue.

How do the current crop of tablets compare?
There's a pretty big range in IDC's and Gartner's definitions if you compare the features of a few of the recently announced or released tablets intended for consumer use.

An iPad has a 9.7-inch screen, runs a version of the iPhone OS, has an ARM-based processor. The JooJoo, which launched earlier this year, has a 12.1-inch screen, a home-brewed browser that functions as an OS, and an Intel Atom processor. The HP Slatewill run Windows 7 (or WebOS), an 8.9-inch screen, and an Atom processor.The Dell Streak has a 5-inch screen, an ARM-based processor, and runs Google's Android--but curiously is being sold through a wireless carrier. Acer has hinted that it has a similar plans for its forthcoming 7-inch Android tablet.

Sounds like the Dell Streak is really a smartphone. Is it?
The Streak is an interesting case. Dell calls it a tablet. It has a 5-inch screen, which is on the large side for a smartphone. But it also runs Android, a limited mobile OS, and can make phone calls--it comes with 3G service with O2 in the UK. According to Gartner's definition that would be a smartphone. It's also very similar to Dell's smartphone, the Mini 3, which also runs Android and has a screen just 2 inches smaller. Lance Ulanoff at PC Mag pointed this out earlier.

To make matters slightly more confusing, Archos has a very similar 5-inch tablet that also runs Android, though it's definitely not a phone. Save for the 3G radio and the camera, the Archos 5 is essentially identical features-wise to the Streak.

So where does the iPad fit in?
According to Steve Jobs, the iPad is not a computer. At its unveiling, he put it in "a whole new category of devices." He has said it's supposed to do all the things that Netbooks were trying to do but "better." Sure, that's just a lot of marketing speak, but he's also partially right: The iPad isn't as useful as a laptop, it's not a Netbook, and it doesn't focus on doing one particular thing well, like an iPod or a Kindle. It has a 9.7 -inch screen, runs a version of iPhone OS, which is not a full desktop operating system, and in terms of features, is a combination of an iPod Touch and an e-reader. It's not quite a PC, and it's definitely not a smartphone. It does, however, inform the definition of what both Gartner and IDC refer to as a "Web tablet" or "media tablet."

Why do Dell, HP, and Apple define "tablet" differently?
Because they're trying to sell a product. And since you likely already own a laptop and a smartphone, they want to introduce you to a new consumer device that you'll want to buy.

Some of these gadget makers are trying to distance themselves from the traditional idea of a tablet PC, which never took off the way Microsoft had envisioned. Apple is trying to distance its iPad from the idea of it being a PC at all, in terms of features, connectivity, and even the ability to run traditional PC browser plug-ins like Adobe Flash. Dell is, for whatever reason, not defining its Streak as a phone even though it's being sold through a wireless carrier. Perhaps it's trying to ride the coattails of what is now a very buzz-worthy category?

HP, on the other hand, is still trying to figure it all out. The company had demonstrated the HP Slate with Windows 7 at CES, which at the time seemed like a straightforward traditional tablet PC. But since buying Palm and promising that Palm's mobile operating system, WebOS, would appear on an HP Slate,the company has been curiously silent about the Windows 7 tablet. That's likely a sign that they're--understandably--still trying to sort things out. 

Much like the rest of the industry.