We're coming up on the one-year anniversary of the iPhone 's release, so people who feel strongly about the popular smart phone have had plenty of time to weigh in with their wallets -- it's been a consistent seller since its release last June 29 -- or with epithets. (Remember the early description of iPhone fans as "iPhonies?")

In the past 11-plus months, seemingly everyone has offered an opinion about the iPhone, usually colored by which side of the Microsoft-Apple divide they're on. One of my favorites came from Microsoft CEO Steve Ballmer : "There's no chance that the iPhone is going to get any significant market share. No chance." Mac fans, myself included, dismissed this as iPhone envy, but even we've been taken by surprise at how quickly the iPhone seems to have gone mainstream.

Chances are, Palm CEO Ed Colligan is among the surprised. Months before Apple's iPhone announcement in January 2007 , he said, "We have learned and struggled for a few years here figuring out how to make a decent phone. PC guys are not going to just figure this out. They are not going to just walk in."

Maybe PC guys couldn't figure it out, but Apple certainly did.

Not only is the iPhone introducing Apple technology to a whole new audience, it's grabbing buyers who had previously shied away from smart phones because the devices are often needlessly complex. It's even infiltrating markets Apple hasn't much targeted, including business - long the territory of Microsoft, Palm and Research In Motion, whose BlackBerry remains the poster child of corporate communications.

Since the iPhone's release, I've spent countless hours debunking an amazing amount of FUD -- and just about as much time answering questions about how the device works and why it's different from the competition. The questioning has grown sharper since Apple announced plans for its iPhone Software Development Kit (SDK) in March. Suddenly, sales seemed to jump, companies started testing it out, and even here at the media company I work for, I quickly found myself supporting a bevy of iPhones.

With a solid combination of advanced technology and ease of use, it became almost ubiquitous, no doubt spurred by Apple's popular ad campaign. Despite the media blitz, a lot of people still have little idea what it is, how it works and where it's taking the mobile-wireless industry. With that in mind, I pulled together this FAQ to help you sort through some of the details. The first question I always get is the easiest: "Oh, dude, is that an iPhone?" After I tell them it is, the quizzing begins.

For more enterprise computing news, visit Computerworld. Story copyright Computerworld, Inc.