More info: Provides SSL AES 256-bit encryption behind the firewall. For business and enterprise accounts, files are stored encrypted with automatic redundancy. File size limits: 100MB for the free accounts, 1GB for paid personal accounts; Business editions have 2GB file size limit. Box allows document editing in the cloud through third-party apps, such as Zoho.
Free cloud storage: 5GB
Extra storage: "Pro" accounts range from 100GB, $9.99/month or $99/year, to 500GB for $49.99/month or $499/year. "Teams" account, 1TB for $795/year for 5 users and $125 for each additional user.
More info: One of the best-known public cloud storage offerings, Dropbox uses SSL AES 256-bit encryption for its Pro and Teams editions. No limit on file size when uploading from the desktop application, which works on Windows, OS X and Linux; 300MB limit when uploading from the Dropbox website. Get 500MB of extra free storage when friends register, up to 16GB. Dropbox does not allow editing of documents directly in the service.
MORE DROPBOX: Dropbox upgrades security with two-factor authentication
Name: Google Drive
Free cloud storage: 5GB -- Google Docs and files converted to Google Docs do not count against storage limit. 1GB of free photo video storage in Picasa Web Albums, unlimited storage of photos and videos (up to 15-minute videos) in Google+.
Extra storage: 25GB, $2.49/month; 100GB, $4.99/month; 200GB, $9.99/month; 1TB, $49.99/month; 16TB, $799.99/month.
More info: Google Drive allows users to store a lot more files in its cloud for free if the files are Google Docs. In many cases, files can be converted to this format simply by copying them into a Google document. Drive does have some file limits, including 2MB for converted files, or 10MB for non-Google Doc files. Spreadsheets have a 20MB limit, or 256 columns. Google Doc files can be edited in the application, but third-party apps are needed to edit non-Google Doc files, such as Microsoft Word files.
Free cloud storage: 50GB
Extra storage: Pro edition features 250GB for $4.50/month, and Business edition offers 1TB for $49/month.