Online Backup, also known as remote backup, is a method of offsite data storage in which files, folders, or the entire contents of a hard drive are regularly backed up on a remote server or computer with a network connection. A number of companies provide online backup services for subscribers whose computers are connected to the Internet, automatically copying selected files to backup storage at the service provider's location. This is sometimes called Web-based backup.

Chances are you have a lot of important stuff on your computer like financial documents, email, digital photos, music and more. Unfortunately, computers are vulnerable to hard drive crashes, virus attacks, theft and natural disasters, which can erase everything in an instant. One in every ten hard drives fail each year. The cost of recovering a failed hard drive can exceed $7,000, and success is never guaranteed.                      

Local backup to external or optical drives is an excellent practice, but it can't always protect your precious data. If there's a fire or flood or tsunami where you keep your computers and PCs, you too can say good-bye to all those digital photographs, your music collection, and anything else you've backed up locally—even if you're smart enough to use backup software (see our file-and-folder backup software roundup for advice on which app to choose) to back up to another on-site device, like a hard-drive or NAS box. You can, of course, store an external hard drive in a safe-deposit box, but that's a hassle, and chances are you won't update it monthly, let alone daily—and certainly not every time you update a file. If you want near-real time off-site backup, an online backup service is the way to go

The rationale behind online backup is simple. By frequently (or continuously) backing up data on a remote hard drive, the risk of catastrophic data loss as a result of fire, theft, file corruption, or other disaster is practically eliminated. With a high-speed Internet connection and a Web browser interface, the remote files and folders appear as if they are stored on an external local hard drive. Encryption and password protection help to ensure privacy and security.

For the home and small business computer user, online backup services may be unaffordable if the intent is to totally back up a hard drive on a frequent basis. This problem can be mitigated by backing up only the most critical or often-changed files online, and using physical offsite backup methods for less important or infrequently changed files. For medium-sized and large enterprises or for particularly valuable data, the cost of online backup can prove to be a wise investment.

Carbonite Online PC Backup - tries to make remote backup simple and affordable. Setting it up is a breeze, and restoring a file here or there is also a snap. But restoring a lot of data to a different PC presented some obstacles.

HP Upline - This easy-to-use, reasonably priced online backup service also lets you do local media backups and file sharing, but it lacks important features, like version saving, open-file backup, and the ability to resume interrupted file uploads.

IDrive - Getting started with IDrive might be more confusing than with any other online backup service, but IDrive partly redeems itself with quick uploading and many extras not found elsewhere.

MozyHome Online Backup - Mozy offers reasonably priced unlimited online backup that's highly configurable, but it could stand some usability improvements.