“Cloud” data is stored on hard drives (much the way data is usually stored). And yes, it’s probably more secure than conventionally stored data.
What makes cloud storage different? Instead of being stored directly on your own personal device (the hard drive on your laptop, for example, or your phone), cloud-based data is stored elsewhere — on servers owned by big companies, usually — and is made accessible to you via the internet.
When people think of cloud computing, they often think of internet-connected public clouds run by the likes of Amazon, Microsoft and Google. (If you use Gmail, Dropbox or Microsoft’s Office 365, you are using a cloud service.) There are also consumer clouds that, for example, hold your pictures and social media posts (think of Facebook or Twitter), or store your music and email (think of Apple or Google).
Each of these companies has cloud computing systems — computer servers and storage devices, connected with computer networking equipment — that span the globe. (Facebook’s systems can allow more than one billion people to interact with them.) Your data is in their computers, usually stored in a regional data center close to where you live.
Individual companies can also have their own clouds, called private clouds, that employees and customers access, usually over the internet and on their own private networks.
Storage aside, computing clouds can also process information differently; they have special software that enables workloads to be shared among different machines. Your Facebook photos, for example, don’t have a permanent home on a specific chip, but may move among computers.
That is a big deal. When workloads are shared, computers can run closer to full capacity, with several programs going at the same time. It’s much more efficient than stand-alone computers running one job at a time.
For the people running the computers, it doesn’t really matter where the data or the programs are at any one moment: The stuff is running inside a “cloud” of computing capability. Ideally, if one machine fails, the operation moves over to another part of the system with little downtime.
Nowadays, computing clouds are everywhere — which is one reason people worry about their security. We hear more and more often about hackers coming over the internet and looting the data of thousands of people.
Most of those attacks hit traditional servers, though. None of the most catastrophic hacks have been on the big public clouds.
The same way that your money is probably safer mixed up with other people’s money in a bank vault than it is sitting alone in your dresser drawer, your data may actually be safer in the cloud: It’s got more protection from bad guys.
In the case of the big public clouds, the protection is the work of some of the world’s best computer scientists, hired out of places like the National Security Agency and Stanford University to think hard about security, data encryption and the latest online fraud.