The word "laptop" is getting somewhat brushed aside for a truckload of new, confusing categories.
The Apple iPad falls into the slate (some people say tablet) category of portable personal computers, because, unlike a laptop, it doesn't have a hardware keyboard.
Another key difference: To type and to navigate through files and photos on the iPad, you touch its screen in the same way you operate an iPhone or iPod Touch. That's possible on some laptop models, but not many.
2. How is the iPad different from e-readers like the Kindle?
Reading digital books on "e-readers" like the Amazon Kindle is becoming increasingly popular. The iPad acts like an e-reader and like a personal computer, but there are some notable differences between the two.
For one, the iPad has a color display. The Kindle, by contrast, is only black-and-white. Some people think the iPad, partly for this reason, will be popular with students who read textbooks with colorful diagrams. Others say the Kindle's screen, which isn't backlit, will be easier on the eyes over long periods.
There's an aesthetic difference, too: The iPad will display books horizontally, with two pages showing, or vertically, zooming in on a single page of text. The Kindle only works in vertical mode.
Perhaps more importantly, the devices access books from different online bookstores. iPad users buy books from Apple's new digital bookstore, called the iBookstore, which supports an open e-book format called ePub. Kindle users must buy their books from Amazon.com.
3. How much does the iPad cost?
Prices range from $499 to $829. The more expensive versions have more storage space, which means you can put more music and videos on the device.
iPads that connect to the Internet with Wi-Fi only are less expensive than those that can connect through Wi-Fi and through AT&T's mobile Internet network.
4. Do you have to sign-up for an AT&T contract when you buy the iPad?
You don't have to buy an AT&T mobile Internet contract to purchase the iPad.
If you buy a Wi-Fi-only version of the iPad and have a Wi-Fi connection at home, or you want to use the iPad primarily at coffee shops or public places that have wireless Internet connections, then you probably won't have to deal with AT&T at all.
Pricier versions of the iPad are able to connect to AT&T's mobile 3G network, allowing them to browse the Web from many more locations.
Surprisingly, you don't need a contract with AT&T to use this service, either.
Users can pay by the month and cancel at any time without penalty, Apple CEO Steve Jobs said at the iPad unveiling. The unlimited data plan with AT&T costs $29.99 per month.
The Wi-Fi-enabled iPads go on sale on Saturday. The AT&T-enabled iPads will ship in late April, according to the online Apple store.
4. If there's no keyboard, how do you type on the iPad?
Instead of being a piece of plastic with physical keys, the iPad's keyboard is a graphic that pops up on the device's touch-sensitive screen -- an interface that will be familiar to iPhone and iPod Touch users.
iPad users type by touching pictures of keys on the screen. The iPad keyboard is about the same size as the one on your desk, but you can't feel the keys.
When he unveiled the device in January, Jobs said the iPad is "a dream to type on." But some bloggers, including this writer, have complained that the iPad's touch-screen keyboard is difficult to use.
5. Can you create documents, spreadsheets and presentations with the iPad?
Apple created a new suite of "apps" specifically for the iPad. These iWork programs, which cost $9.99 each, let users create documents, edit spreadsheets and create business presentations from the iPad.
It's unclear how easy these programs will be to use. Some reviewers say it's easy enough to compose business documents on the iPad. Others say serious users will need another computer to be productive.
The iPad has a Wi-Fi connection, which, in theory, could be used for printing documents wirelessly through your printer. There is some debate online about what apps will perform this function.
6. Can you view any Web site on the iPad?
A certain format of online video, called Flash, does not play on the Apple iPad.
While there are some workarounds for this, many Web sites are redesigning themselves, using a type of code called HTML5, so they will work on the iPad.
That code allows video display on the device, but you may notice some sites, including this one, will have holes because the iPad doesn't support Flash video.
7. Will the iPad replace my current computer? Or do you need both?
Some technology writers and critics say the iPad is an all-in-one machine. Others argue that it's more of a portable accessory, and that most computer users need a desktop or laptop computer in addition to an iPad.
What works for you really depends on what you use your computers for. If you spend a lot of time typing or creating things with your computer, it may be easier to use a laptop. If you just want to surf the Web, read books, play games, watch movies or send an occasional short e-mail, the iPad might work.
Apple and others sell keyboards that can be attached to the device in case you need to write a longer e-mail and don't want to fiddle with the touch-screen keyboard.
8. Is the iPad lighter and smaller than other laptops or e-readers?
The iPad will be about a half-inch thick and weigh about 1½ pounds.
Its screen is 9.7 inches across, when measured diagonally.
That's smaller and lighter than some laptops. A 10-inch netbook from Dell is similar in size but weighs about a pound more.
Amazon's Kindle DX is slimmer than the iPad, at only a third of an inch thick, and it weighs slightly less: 1.2 pounds, according to Amazon.
Its screen is the same size as the iPad's, but it doesn't display color.
9. Can you subscribe to newspapers and magazines on the iPad?
Some magazines and newspapers have said they hope the iPad will help save their struggling industries. A number of them have reformatted their publications for the iPad's screen and are offering new digital subscription plans.
The Wall Street Journal, for example, will charge $17.99 per month for an iPad subscription to its newspaper.
10. Are there iPad alternatives?
Apple is not the only computer maker offering a slate device. Some are on the market now and others will come out soon.
HP briefly showed off its slate computer before an audience at the Consumer Electronics Show in January. Dell has announced plans to make a personal computer in the slate category.