How Cloud Computing Works

Sun Microsystems’s slogan is “The network is the computer,” and that’s as good as any to describe how cloud computing works. In essence, a network of computers functions as a single computer to serve data and applications to users over the Internet. The network exists in the “cloud” of IP addresses that we know as the Internet, offers massive computing power and storage capability, and enables widescale group collaboration. But that’s the simple explanation. Let’s take a look at how cloud computing works in more detail.

Understanding Cloud Architecture

The key to cloud computing is the “cloud”—a massive network of servers or even individual PCs interconnected in a grid. These computers run in parallel, combining the resources of each to generate supercomputing-like power. What, exactly, is the “cloud”? Put simply, the cloud is a collection of computers and servers that are publicly  accessible via the Internet. This hardware is typically owned and operated by a third party on a consolidated basis in one or more data center locations. The machines can  run any combination of operating systems; it’s the processing power of the machines that matter, not what their desktops look like.

Understanding Cloud Storage

One of the primary uses of cloud computing is for data storage. With cloud storage, data is stored on multiple third-party servers, rather than on the edicated servers used in traditional networked data storage. When storing data, the user sees a virtual server—that is, it appears as if the data is stored in a particular place with a specific name. But that place doesn’t exist in reality. It’s just a pseudonym used to reference virtual space carved out of the cloud. In reality, the user’s data could be stored on any one or more of the computers used to create the cloud. The actual storage location may even differ from day to day or even minute to minute, as the cloud dynamically manages available storage space. But even though the location is virtual, the user sees a “static” location for his data—and can actually manage his storage space as if it were connected to his own PC.

Cloud storage has both financial and security-associated advantages. Financially, virtual resources in the cloud are typically cheaper than dedicated physical resources connected to a personal computer or network. As for security, data stored in the cloud is secure from accidental erasure or hardware crashes, because it is duplicated across multiple physical machines; since multiple copies of the data are kept continually, the cloud continues to function as normal even if one or more machines go offline. If one machine crashes, the data is duplicated on other machines in the cloud.

Understanding Cloud Services

Any web-based application or service offered via cloud computing is called a cloud service. Cloud services can include anything from calendar and contact
applications to word processing and presentations. Almost all large computing companies today, from Google to Amazon to Microsoft, are developing various types of cloud services. With a cloud service, the application itself is hosted in the cloud. An individual user runs the application over the Internet, typically within a web browser. The browser accesses the cloud service and an instance of the application is opened within the browser window. Once launched, the web-based application operates and behaves like a standard desktop application. The only difference is that the application and the working documents remain on the host’s cloud servers.

Cloud services offer many advantages. If the user’s PC crashes, it doesn’t affect either the host application or the open document; both remain unaffected in
the cloud. In addition, an individual user can access his applications and documents from any location on any PC. He doesn’t have to have a copy of every
app and file with him when he moves from office to home to remote location. Finally, because documents are hosted in the cloud, multiple users can collaborate on the same document in real time, using any available Internet connection. Documents are no longer machine-centric. Instead, they’re always
available to any authorized user.

Excerpt from Cloud Computing: Web-Based Applications That Change the Way You Work and Collaborate Online