Introducing Cloud Computing
You'll begin your CompTIA Cloud+ (CV0-003) certification exam journey with a general overview of cloud computing. With a strong understanding of cloud terminology and architectures, you'll better understand the details of the cloud, which in turn means that you'll be better prepared for the Cloud+ exam and be effective when planning, deploying, and supporting cloud environments.
Let's start by briefly looking at where cloud sits in the broader scope of the IT world. Before cloud computing, organizations had to acquire the IT infrastructure needed to run their applications. Such infrastructure included servers, storage arrays, and networking equipment like routers and firewalls.
Options for where to locate this infrastructure were limited. An organization with an ample budget might build an expensive data center consisting of the following:
- Racks to hold servers and networking equipment
- Redundant power sources and backup batteries or generators
- Massive cooling and ventilation systems to keep the equipment from overheating
- Network connectivity within the data center and to outside networks such as the Internet
Organizations that are less fiscally blessed might rent physical space from a colocation (colo) facility, which is just a data center that leases rack space to the general public. Because colo customers lease only as much space as they needābe it a few rack units, an entire rack, or even multiple racksāthis option is much cheaper than building and maintaining a data center from scratch. Customer organizations just have to deal with their own IT equipment and software. To put it in marketing terms, think of a colocation facility as ādata center as a service.ā
Cloud computing takes the concept of a colocation facility and abstracts it even further. Instead of acquiring your own IT equipment and leasing space for it from a colo, an organization can simply use a cloud service provider. In addition to providing and managing the data center infrastructure, a cloud service provider (or just provider for short) also handles the IT hardware infrastructureānamely servers, storage, and networking. The consumer of the cloud services pays fees to use the provider's equipment, and such fees are typically based on usage and billed monthly. In this chapter, we'll dive further into the details of how cloud computing works and how an organization might use the cloud instead ofāor in addition toāa traditional data center or colo model.
Related to the data center versus cloud distinction, there are two terms that you need to know. On-premises (on-prem) hosting refers to an organization hosting its own hardware, be it in a data center or a colo. In contrast, cloud computing is an example of off-premises (off-prem) hosting, as the hardware resources are not controlled by the organization that uses them. To make this distinction easy to remember, just equate on-prem with data center and off-prem with cloud.
This book will reference the National Institute of Standards (NIST) SP 800-145 publication ( https://doi.org/10.6028/NIST.SP.800-145 ) as the main source of cloud computing definitions. NIST defines cloud computing as follows:
ā¦ a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
Pay close attention to that last sentence. The reference to āminimal management effort or service provider interactionā is code for automation. Unlike a traditional data center or colocation facility, using the cloud doesn't require someone to physically go to a facility to install servers or plug in cables. There's no need for āremote handsā because cloud providers offer self-service management consoles that do the provisioning for you. When you think about it, cloud providers are really just providing automation-powered managed services for nearly every conceivable IT need.
In this study guide, you'll take a close look at all aspects of cloud computing as you progress on your journey to obtaining the Cloud+ certification. As an analogy to cloud computing, think of the services you get in your home through utilities, such as electricity and water services. You are probably not involved in the details of how these services are created and delivered; you turn the water faucet on and off, and pay only for what you use. Cloud computing follows the same principle, albeit appl...
