We introduced the idea of cloud computing in Chapter 1. Cloud computing is a paradigm in which computing system resources (computing power, storage space, etc.) are provided by a third party and managed through Internet communication.

The term cloud computing comes from diagrams, like FIGURE 15.13, that show network communication going through an amorphous cloud to get to a resource. The point is that we don’t necessarily know or care where the resource is or how the communication gets routed; we just want the resource.

You may already use the concept of cloud computing on a small scale with an email account. For example, an email service such as Google’s Gmail stores and manages your email on its network servers. When you use a browser or other email client to access your email, it’s downloaded onto your computer or mobile device. That way, you don’t have to worry about what computer you’re using or where you are when you access it.

Cloud computing takes that concept to a larger scale. A business or individual can store not just email but also documents, images, videos, etc. on network servers instead of a local machine. The benefits of this approach are that the management of the devices on which this information is stored is largely left to someone else, and that it is available wherever an Internet connection can be found.

Cloud services usually provide other benefits as well. A cloud service typically makes backups of your data, relieving you of that responsibility. Some provide web hosting capabilities as part of their service. Some support synchronization services that keep things like browser bookmarks in sync on multiple devices automatically.

Cloud computing has become a standard mode of operation for many businesses. It relieves the business of potentially expensive hardware and software resources, as well as the personnel needed to manage the data in house. The dominant providers of cloud computing are Amazon Web Services, Google Cloud, and Microsoft Azure.

There are different types of cloud services available:

• Public cloud—accessible by any subscriber

• Private cloud—established for a specific group or organization, limiting access to that group

• Community cloud—shared among two or more organizations with similar needs

• Hybrid cloud—some combination of the above cloud types

Some cloud services are free, and services that charge a fee vary in cost significantly. If you’re interested in cloud computing, research your options carefully.