The Cloud – A Guide for Beginners

Hold on – if you know what PaaS is or already know the concept of the Cloud being an “On-demand, self-service” model of resource management, jump to the end of this post or check out our free intro to Cloud course.


Many people think they have “the Cloud” figured out. It’s an off-site storage system, like Dropbox, right? Unfortunately, no. While storage is a cornerstone Cloud resource, this is really just scratching the surface of what the Cloud can do. But it is a fine place to start. Cool. So where is the Cloud? Well, when you upload a file it is sent through a network of computers (the Internet) and deposited on a computer (or possibly a few) in a data center.

What is a Data Center?

These computers (or servers as they are usually called) are housed in enormous warehouses that often have their own power, cooling systems and a lot of serious security. (Check this video tour of a Google data center if you’d like to learn more.) The Cloud is made up of the multitude of internet-connected data centers (or rather their servers) all around the world.

The thing that is interesting here, is now that you’ve uploaded a file to this server system in a data center (the Cloud), you can access if from any network connected device that has the correct interface. In some cases, you can simply share a URL (an internet address) and retrieve the file. In other cases an interface is necessary or can be used to make life more convenient (like Dropbox and its relatives).

The Cloud is More Than Just Storage

So now you know that the Cloud is a system of remote computers that allows you to store data. But, there is more to it than that. More generally the Cloud provides you on-demand access to several different service types. Storage-as-a-Service is important, but really just one of the Cloud’s many functions.

More generally, the Cloud has the potential to give users access to “pools” of Storage (but you knew that), Compute and Network resources.  These are the building blocks, the infrastructure, that allow the Cloud to create all kinds of other services.  There is a broad term called Infrastructure-as-a-Service that describes this.

The compute resource gives us access to computing power that quite possibly goes beyond what we can afford to buy. The “pay for just what you need model” can give you access to a supercomputer’s power for a short period of time for just a few dollars.  Most people don’t mess with the network services unless they are building their own cloud. Still, having access to network resources allows advanced and professional cloud users and operators to build connected computer systems that tie computers and storage systems together.

The Cloud is More Than Just Infrastructure Building Blocks

Some Cloud users take that infrastructure service and build a connected set of computers and storage systems to serve up websites or applications.  This can take a lot of work and many people that want to build applications really just want to code their app or build their website and not have to deal with figuring out the infrastructure that will make it go. This is where a Platform-as-a-Service cloud comes in. This is probably the least understood cloud platform as most of us use apps, we don’t build them.  But services like WordPress, Wix or Squarespace provide platforms to build websites. You still need to massage the pieces into what you want, but you aren’t worried about where your website is loaded or its database is housed or even how the network allows users to access your site. This is the benefit of a Platform Cloud.

Finally There is the Cloud Most of us use.

Software-as-a-Service is really the major function of the Cloud – even more than the storage that seems to have stolen the spotlight. All those apps you are running on your phone, tablet or computer? Most likely they are running in the Cloud. Even if you’ve had to install something locally on your device, this is often an interface- a way to communicate with the main part of the application you are using. The interface lets you select or request things, but much of the processing may, in fact, be happening in the Cloud. When you post an update on Facebook/Twitter/Instagram/Snapchat you are sending this information to be housed in the Cloud that hosts that particular application. This is very Dropbox-ish in that you are essentially storing your update in the Cloud and you can now see that updated version of your application (as can your friends and followers) from any device they use to interface with the app.

However when you ask for data back – when you search online for something, for example, you are using the processing power of the cloud to do computing work for you, in this example, finding the (supposedly) best answers to your query from all of the data available to Google (or Yahoo, Bing, DuckDuckGo, etc.). Your phone, tablet, laptop, whatever would take ages to crunch all the possible data and get an answer, but the power of the Cloud is to run the query and return to the answer to your device. Depending on the process, the behind the scenes computing might have taken just part of a single server or used the power of dozens of computers to quickly finish the task and then move on to the next. This is perhaps the real power of the cloud – shared resources that can be used for on-demand tasks when and where you want those tasks completed. To put this more concisely, you get on-demand, self-service access to pooled resources (compute, network and storage) and that is the Cloud.


O.K. Now that you have a basic idea of the Cloud, want to dive a bit deeper? Through the end of this month, our foundational Introduction to Cloud Computing course is free. Just sign up for a free account and learn the differences between IaaS, SaaS and PaaS in greater detail, learn the 5 components needed for a virtualization system to truly be “a Cloud,” know how a Public, Private and Hybrid Cloud differ. To sign up for your free account, click the button below.

I want to know more about “the Cloud.”
John Starmer, Director of Education @john_starmer