In a swarm of speculation and hype unseen since June 29, 2007, when Apple unleashed the iPhone on the world, Apple's new device, the iPad makes its debut.

There is no shortage of opinions on the device, and no shortage of questions as to what it does or doesn't do, and how well it does the things it sets out to do. No matter what your opinion, here are the five biggest things that you need to know about the iPad:

1. Get In Line. Or Don't

It's no big secret that the iPad will be hard to come by in the first few weeks, well, unless your name is Steve Wozniak.

First off, it's unclear as to how many iPads have even been produced. What is known is that the opening day orders are sold out and that even big-name retailers, such as Best Buy are getting a mere pittance of devices. Apple Stores are already seeing long lines, with one man in New York queuing up on Tuesday. Of course, that same guy is credited to being the first in line for an iPhone.

2. The Device Defies Explanation

For those lucky enough to land an iPad, a question very well might be nagging—what exactly is it?

Yes, it's a tablet computer, which is a device that is equal parts infant and phoenix. But what is the iPad's competition? Traditional laptops? Netbooks? Amazon's Kindle? Apple's own iPod Touch?

The answer is—all of the above. The answer also is—none of the above. Steve Jobs said at the iPad unveiling earlier this year that it fits in a market between smartphones and traditional computers.

Walt Mossberg said in his review that the iPad "has the potential to change portable computing profoundly, and to challenge the primacy of the laptop." However, he goes on to say that in order to do that, the iPad "will have to prove that it really can replace the laptop or netbook for enough common tasks, enough of the time, to make it a viable alternative."

David Pogue echoed that sentiment, saying that "the iPad is not a laptop. It’s not nearly as good for creating stuff. On the other hand, it’s infinitely more convenient for consuming it."

The key here is the onscreen keyboard. While Jobs boasts that it is "a dream" to type on, and that it is the size of a typical laptop keyboard, there is a clear difference between banging out a 140-character text or tweet and a 1,400-word paper, article, or even email. The former is easily attainable, even on the worst onscreen keyboard. Is the latter going to be easy, even on the best onscreen keyboard?

3. It Has Limits

The iPad shares the same problem as the iPhone operating system—the ability to do more than one task. Users will only be able to run one app at a time, although the hot rumor is that iPhone OS 4.0 will have some degree of multitasking.

The iPad will let users play music while doing other things, but many abilities that have become the norm for traditional computing and Web browsing just aren't going to be on the iPad. Among them: tabbed browsing, videos on webpages, and the ability to have a pop-up window.

The biggest hurdle could be the lack of Adobe Flash support, which is the backbone of a few sites that have a nice audience—Hulu and ESPN. Apple is throwing itself behind the alternative to Flash—HTML5—and makes a workaround for Flash-based sites such as YouTube and Vimeo with an app.

Getting back to the idea of iPad versus a netbook or laptop, both of those offer "normal" functionality out of the box. Also, for the tech savvy, the design is equal parts gorgeous and frustrating. The latter coming into play in regards to the concept of upgrading memory or changing the battery, both of which are all but impossible for everyone except an expert.