Like iCloud, SkyDrive serves a lot of functions. If you just want access to documents or media files, it offers simple online storage accessible from the Web. If you want the same set of files replicated on multiple PCs it provides folder syncing. For users of Windows 8 and Windows Phone, it backs up settings. Because of this diversity of function, there are several different cross-sections from which you can view the service—by type of data, client, or function. The data types include documents, photos, video, music, or settings. The clients include computer, mobile, and Web, and the functions are things like syncing, viewing, playing, and simple storage. Let's take a look at the service from these various angles.

Everyone gets a SkyDrive account--well, everyone who's created a Microsoft account, which includes everyone who's signed up for a Hotmail or Outlook.com account. All users get 7GB free storage space, and, if you're a longtime SkyDrive account holder (since before April 22, 2012), you get 25GB free. This compares with 5GB free for iCloud and Google Drive (though if you convert docs to Google format, storage is free), and 2GB for Dropbox. You can add 20GB to SkyDrive for $10 a year, and 100GB for $50. Here's how the pricing compares with the other services:

Device Syncing
Microsoft likes to refer to SkyDrive as a "device cloud" and with Windows 8 PCs and Windows Phones, the moniker makes sense. The service can sync settings and apps on those types of devices, while clients for iOS, Android, and Mac OS X give users of those devices access to the files stored in SkyDrive's online folders. Like iCloud for iPhones and iPads, SkyDrive lets Windows Phone users automatically upload photos taken with the phone's camera to SkyDrive's camera roll, so that the photos are quickly available for viewing online, in a SkyDrive folder on a PC, or in a Windows 8 PC's Photos app.

Google Drive and Android Play don't provide this functionality, which, once you've gotten accustomed to it, is pretty slick and convenient. And in the SkyDrive Web interface, you can view the photos as a slideshow, and even see a map of where they were taken along with EXIF camera info. A similar Web interface of this type is completely lacking in Apple's iCloud, though that may change with iOS 6.

Another service in the realm of device syncing is the ability to sign into your account and magically reproduce a previous machine you've set up—color and background themes, social accounts, user photo, browser favorites and history, and even apps. SkyDrive accomplishes this for both Windows 8 PCs and Windows Phones. In Windows 8, the service goes even further, by allowing third-party apps to take advantage of your cloud storage. Apps and sites can even use the service for single sign-on with your permission.

SkyDrive Clients
SkyDrive is built into Windows 8 and Windows Phone, as long as you've signed into a Microsoft account. But what if you use other technology platforms? SkyDrive includes apps for not only Windows 7 and 8, but for Mac OS X, iOS, and Android. For other mobile platforms such as Blackberry, a mobile Web interface is available, and for desktop access when you're not at your own computer, a full feature Web app is available. The last is particularly important, and one thing that's long disappointed me about Apple's iCloud: Why can't I access photos in my iCloud Photo Stream from a Web browser, if the stuff is actually in the "cloud?"