Swapping on-site, tangible data storage such as hard drives, CDs, DVDs, and flash drives for remote, on-demand delivery of files is increasingly commonplace. Streaming video is pushing aside DVDs. The newest Apple iMac desktop computer doesn’t have an optical drive and can’t read CDs or DVDs. A new generation of laptop computers -- Chromebooks -- run on Google's browser-based, cloud-focused Chrome OS. Software is accessed through the Internet. A Samsung Chromebook has just 16GB of flash memory, which means most users will store most of their videos, music, photos, and documents on Google Drive. It seems everything is moving to the cloud.

A growing number of businesses are moving to the cloud  for everything from applications to data storage, drawn by flexibility of pay-for-use billing and the promise of lower costs.

Most individuals use cloud computing to backup their home computer files. Such online backup services “are afoot in the door with cloud computing,” says Sean Miller, IT Solutions Engineer for EarthLink, a provider of cloud computing services.

Your family photos are safer in the cloud than on your hard drive, say Miller and other experts.

Hackers who want to steal your data must climb much higher firewalls to get into a data center than they would to steal from your home hard drive. Most cloud providers like EarthLink provide for a multilayer approach to Cloud security. Most cloud providers such as EarthLink have layers and layers of firewalling, intrusion prevention systems, intrusion detection systems and other security practices, Miller says.

Your data -- photos, songs, term papers, business records -- are stored in vast buildings filled with racks and racks of servers. Each data center -- or Storage Area Network -- stores and replicates your data. And all that information is stored, and replicated, at several data centers scattered across the country.

If a data center is struck by disaster, “the vast majority of the time, a customer would never notice it,” says Bob Leibholz, Senior Vice President of Sales and Business Development for Intermedia, which provides cloud services to small businesses.

Data centers are protected by physical security that may include retina scanners, backup power generators, backup cooling systems and multiple network providers coming into the building.

Still, no system is 100 percent reliable. A recent study by the International Working Group on Cloud Computing Resiliency stated showed that about 568 hours of downtime between 13 major cloud carriers since 2007 cost customers about $72 million.

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