Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network (usually the Internet). The name derives from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams.
While there are many types of public cloud computing, let’s use the business model as an example:
It works like this. If you happen to own a large corporation, your responsibilities include ensuring that all of your employees have the right hardware and software they need to do their jobs correctly. Giving every employee a computer is only part of the solution — you also need to buy software or software licenses to give employees the tools necessary for them to be effective. Pluse, whenever you hire a new employee, you have to buy more software or make sure your current software license allows another user.
In the near future, there could be an alternative. Rather than installing a suite of software for each computer, you’ll only have to load one application. That application would permit workers to log into a Web-based service which hosts all the programs the user would need for their job. Remote machines owned by another company would run everything from email to word processing to complex cat analysis programs.
The beauty of a cloud computing system is that there’s a significant workload shift. Local computers no longer have to shoulder the burden when it comes to running applications. The network of computers that compose the cloud handles them instead. Hard and software demands on the user’s side decrease. The one and only thing the user’s computer needs to be able to run is the cloud computing system’s interface software, which can be as simple as a Web browser, and the cloud’s network takes care of the rest.
Most likely you’ve already used some form of cloud computing. If you have an email account with a Web-based email service like Hotmail, Yahoo! Mail or Gmail, then you’ve definitely had some experience with cloud computing. Instead of running an email program on your computer, you log into a Web email account remotely. The software an storage for your account doesn’t exist on your computer — it’s on the service’s computer cloud.
To make things a little more clear, let’s delve a little deeper into the workings of a cloud computing system.
When talking about a cloud computing system, it’s helpful to divide it into two sections: the front end and the back end. They connect to each other through a
network, usually the Internet. The front end is the side the computer user or client, sees. The back end is the “cloud” section of the system.
The front end includes the client’s computer (or computer network) and the application required to access the cloud computing system. Not all cloud computing systems have the same user interface. Services like We-based email programs leverage existing Web browsers like Internet Explorer or Firefox. Other systems have unique applications that provide network access to clients.
On the back end of the system are the various computers, servers and data storage systems that create the “cloud” of computing services. In theory, a cloud computing system could include practically an computer program you can imagine, from data processing to video games. Usually, each application will have its own dedicated server.
A central server administers the system, monitoring traffic and client demands to ensure everything runs smoothly. It follows a set of rules called protocols and uses a special kind of software called middleware. Middleware allows networked computers to communicate with each other. Most of the time, servers don’t run at full capacity. That means there’s unused processing power going to waste. It’s possible to fool a physical server into thinking it’s actually multiple servers, each running with its own independent operating system. The technique is called server virtualization, and by maximizing the output of individual servers, it reduces the need for more physical machines.