All you need to know about tablet computers

In this product image provided by Sony Corp., the Sony Tablet S is displayed. The Tablet S, which is about the size of an iPad, can double as a universal remote control. The tablet is wedge-shaped, with one thicker than the other. The shape mimics that of a magazine that's been folded over. (AP Photo/Sony Corp.)

Tablet computers began to emerge in the mainstream last year, and now the market is saturated with more than a hundred of them. Although tablet computers have been around for years, they were long considered niche products that were designed mainly for business professionals. And while business-oriented tablets are still all the rage, the latest tablets have consumer-friendly designs popular with everyone from students to soccer moms.

Tablet computing today spans an array of tasks, including watching movies, surfing the web, playing games and performing basic tasks, such as word processing. Finding the right tablet for your needs might seem a daunting task, but knowing the basics can simplify the process.

To begin with, tablet computers take two main forms: convertible tablets and slates. And although the terms tablet and slate are now used interchangeably, this is due in part to the complete dominance of slates in the marketplace and the increasing crossover between the two categories. But the differences are still easy to recognize.

Convertible tablets look like regular laptops or netbooks, but the screen swivels 180 degrees to transform the computer into a touch-screen tablet or, alternatively, some convertible tablets come with detachable (sometimes optional) keyboards or keyboard docks. Slates, on the other hand, get rid of the physical keyboard altogether in favor of a virtual touch-screen keyboard. Slates are typically lighter and more portable than convertible tablets, but the touch-screen keyboard isn't ideal for writing and editing long documents, creating spreadsheets or drafting business memos. Convertible tablets are convenient because they can be used as a laptop or a tablet, but they usually cost more than slates. They also tend to be heavier, although most weigh less than 5 pounds.

The heavy hitter in the tablet world is the Apple iPad 2, the much-hyped successor to the original iPad. While it retains the same price (Apple's suggested retail price starts at $499), the iPad 2 is slimmer, faster and has even better battery life. It also has some downsides -- the camera is not yet up to consumer par and it still lacks support for Flash video -- but most reviews say the iPad 2 easily retains the title of best tablet for now.

However, Apple finally has some tough competition, most notably from tablets with the Android "Honeycomb" OS, such as the Samsung Galaxy Tab 10.1. The iPad 2 may be the most popular and top-selling tablet, but the Galaxy Tab 10.1 (Samsung's suggested retail price starts at $499) is a good alternative for those who prefer the Android operating system. Honeycomb is the first Android operating system designed specifically for tablet computers. The Galaxy Tab 10.1's performance is fast, the display boasts a higher resolution than the iPad, it's a little lighter, a bit thinner and battery life is very good.

There are a number of things that have kept the Samsung Galaxy Tab 10.1 from overtaking the Apple iPad 2. There are still fewer tablet-specific apps for Android devices than there are for the iPad 2, and the Honeycomb OS is still somewhat buggy.

If you decide to purchase an Android-based tablet -- but don't have an immediate need, you might want to wait. NVIDIA is releasing a new quad core version of the chipset used in those machines, code-named Kal-El, which is to be in tablets hitting the market this fall, according to the manufacturer. It is supposed to offer five times the computing power of the existing NVIDIA Tegra 2 chipset used in the most advanced current Android tablets.

Shopping tips:

Beyond the basic differences between tablets, there are other considerations when shopping for a tablet computer. Keep the following in mind to make sure the tablet you purchase is right for your needs:

• Test it in the store -- An onscreen keyboard might sound great until you actually type on it. Likewise, trying a tablet in a store can help you evaluate the display and determine the responsiveness of the touch screen. It also helps to gauge how it feels in your hands.

• Not all tablets support multitouch -- Some tablets, especially older models designed for business users, require the use of a stylus. Many modern tablets recognize finger input, but not all support multitouch technology. Always make sure you know which type of touch screen your tablet uses.

• Evaluate the apps -- If you are buying a tablet to be used for entertainment purposes, make sure it has the apps you want. The Apple iPad 2 is the leader in this category, with more optimized apps than any other tablet. Android tablets can usually download apps from the Android Market, though some cheaper models tend to have difficulty with this.

• Networking options -- Most tablet computers have integrated Wi-Fi, and many offer 3G or 4G connectivity as well. You'll have to pay extra for a 3G/4G data plan, but some (like the iPad 2) don't require a contract. Having 3G/4G connectivity gives you better Internet access away from home. Most newer tablets are 4G compatible, although 4G coverage is generally limited to major metropolitan areas right now.

• Storage -- Apps, music and especially video can eat up flash memory fast. Some tablets let you expand storage (typically via an SD or Micro SD memory card), but others don't.

• Data rates -- Many newer tablets are available for a cheaper price if you sign up for a data contract with a wireless carrier. Make sure you will use mobile broadband before you commit, because data rates can add up quickly. Some carriers offer no-commitment plans that let you pay on a month-to-month basis for access as needed. However, avoiding a contract can leave you open to activation fees if you decide you need mobile broadband access at some point.