The "cloud," which is a shorthand term for remote computing, can be used for anything from finessing a spreadsheet while on the road using multiple devices to collaborating on a report with multiple people all over the world and, probably most important and popular, remote storage, including backup.
Though Amazon, a big player in this space with Amazon Cloud Drive (www.amazon.com/clouddrive), just eliminated the option of free storage, other top cloud storage providers still offer free options, with pay options for more storage and extras.
Apple's iCloud (www.apple.com/icloud) offers 5 gigabytes for free and charges $12 a year for 20 gigabytes, $48 a year for 200 gigabytes, $120 a year for 500 gigabytes, and $240 a year for 1 terabyte. iCloud makes it easy to share iTunes, iBooks, and App Store purchases along with photos and calendars with other users of Apple devices and computers.
Dropbox (www.dropbox.com) gives 2 gigabytes of storage for free. It charges $120 a year for 1 terabyte of storage, which is virtually unlimited for most users. For businesses, Dropbox charges $180 per user per year for unlimited storage. Because Dropbox isn't affiliated with a specific computing platform, unlike some other cloud storage options, it supports a large number of devices, whether they run on Windows, Windows Phone, OS X, iOS, Linux, Android, BlackBerry, or Fire OS.
Google Drive (www.google.com/drive) offers 12 gigabytes of free storage and charges $24 a year for 100 gigabytes and $120 a year for 1 terabyte, with business plans offering unlimited storage available for organizations having more than five users. Google Drive offers convenient and easy-to-use collaboration tools.
Mega (www.mega.co.nz), the current top dog in the free-storage market in terms of sheer capacity, offers 50 free gigabytes.
Microsoft's OneDrive (www.onedrive.live.com) gives users 15 gigabytes of free storage and charges $24 a year for 100 gigabytes, $48 a year for 200 gigabytes, and $84 a year for 1 terabyte. OneDrive's 1 terabyte plan includes a subscription to Office 365 for one PC or Mac and 60 minutes a month of free Skype calls to landline and mobile phones. You can't get better Office-compatibility than with Microsoft Office.
Choosing the best cloud storage plan for you also can depend on which devices you use and how you use them.
Google Drive is tightly integrated with Google Docs. If you're a Google Docs user, Google Drives makes the most sense. It's also a convenient way to collaborate with others at different locations.
OneDrive integrates well with Microsoft Office as well as with Windows 8 and the forthcoming Windows 10. If you're a heavy Office user, OneDrive can be the way to go.
If you're Apple based, iCloud is your best cloud storage option.
Going with brand-name cloud storage from a solid company, at least as your primary cloud option, is more important than in many other areas. You don't want to take the chance of your files going away if a particular provider goes belly up.
Other cloud storage providers exist aside from the ones mentioned above, and there's nothing preventing you from using more than one. Additional options include Box (www.box.com), CertainSafe (www.certainsafe.com), Hightail (www.hightail.com), IDrive (www.idrive.com), and SugarSync (www.sugarsync.com).