The Different Types of Cloud Computing Explained
Types of cloud computing
When people talk about the subject of cloud computing, it can all become quite confusing pretty quickly. One of the main reasons for this is that there are multiple types of clouds available, and they can all provide different capabilities. The three main types of cloud computing are:
1. Public cloud
What is the public cloud?
In simple terms, the public cloud is a vast array of readily available compute resources such as networking, memory, central processing unit (CPU) and storage. These resources are hosted in one of the public cloud vendors globally distributed and fully managed data centers and you can rent these resources to build an IT infrastructure.
These basic compute resources are coupled with managed services like database servers, applications and security systems. The managed services are there for you to rent if you don't want the hassle of setting up and managing the whole solution. The leading providers of this type of cloud offering are Google Cloud Platform (GCP), Amazon Web Services (AWS) and Microsoft Azure, however there are others. Accessing your resources in this type of cloud can be a simple as using a web browser.
Public cloud benefits
One of the great benefits of the public cloud is that the underlying hardware and logic is hosted, owned and maintained by each of those vendors. This means that customers have no responsibility for buying or maintaining the physical components that make up their public cloud IT solutions.
The “pay-as-you-go” model used to charge for these resources makes them a more cost effective solution than owning them yourself as you only pay for what you consume. The ability to scale the size of your solution up to accomodate for the peaks and troughs in usage saves the customer money, and also gives huge flexibility.
Lastly, financially backed Service Level Agreements (SLAs) commit each vendor to a monthly uptime percentage and guarantee of security in line with standards such as GDPR, FIPS, HIPAPA etc. With this in mind, the public cloud vendors have invested, and continue to invest, 10s of billions of pounds in their data centers so they can be provisioned with state of the art fault tolerant power supplies, network paths, storage facilities and automated monitoring and maintenance systems to meet these SLAs.
2. Private Cloud
What is a private cloud?
Private clouds are owned and used by single private businesses and organisations. They have traditionally been physically located at the business’s own data centre using its own hardware.
However, a business may employ a third-party provider to host their private cloud on their kit. In that scenario, private cloud does have some similarities to public cloud in that the resources are in a remotely managed data center. However, although these providers will offer administrative services, they will only be able to offer a tiny percentage of the global services of a public cloud.
Private cloud benefits
If the private cloud is being hosted in your own data center then there is the benefit of being able to fully control the entire solution yourself.
As you have complete control over the infrastructure, you can tailor your cloud computing approach to your own preferences and internal processes. Some of the more stringent security and compliance legislation insists on certain types of data and resources being kept inside your own security boundary - a self-hosted private cloud will help to comply with this.
3. Hybrid cloud
What is a hybrid cloud?
A hybrid cloud is the combination of public and private cloud elements connected securely over the internet by virtual private network (VPN) or a dedicated private channel.
For example, you could use the near unlimited storage capacity of the public cloud for storage while data processing could happen on your premises. Or you could extend your computer network in to the cloud to save having to buy in additional permanent hardware.
Hybrid cloud benefits
A hybrid cloud solution offers benefits from the best of both options and makes cloud cloud bursting possible. In the example of extending your private cloud network, this means that if you are running out of compute capacity on premise, it can be supplied by the public cloud. This is a cost-effective way for businesses to increase compute capacity on demand while still utilising the already paid for on premise resources.
Types of cloud services
There are also different types of cloud services which work to solve different problems. There are three main types:
- Infrastructure as a service (IaaS)
- Platform as a service (PaaS)
- Software as a service (SaaS)
and a fourth rapidly gaining momentum:
- Serverless computing
What is infrastructure as a service (IaaS)?
IaaS is the most common first step on the journey to the cloud for a company with an existing IT estate. IaaS essentially allows companies to rent the remote physical and logical (networking) IT infrastructure from a cloud vendor and deploy virtual machines (VMs) which they can then manage. The management of public cloud VMs is similar to when they are hosted on premise, however the need to own or manage any of the physical environment is completely removed. Because of this, existing IT skills are mostly transferable and the pay-as-you-go nature of the public cloud can make this a relatively painless and cost effective way to make the first steps in to the cloud.
IaaS examples
Common examples of IaaS:
- AWS EC2 Instance
- Google Cloud VM Instance (Google Compute Engine)
- Azure Virtual Machine
What is platform as a service (PaaS)?
PaaS enables consumers to create environments on-demand for developing, testing, delivering and managing software and services. This is an extremely efficient way of creating new web or mobile apps, databases and container clusters as administrators don’t need to worry about creating or managing the wider infrastructure.
PaaS examples
Common examples of PaaS cloud services include:
- AWS Elastic Beanstalk
- Google App Engine
- Microsoft Azure Web Apps
- Google Cloud SQL
What is software as a service (SaaS)?
SaaS is a simplistic way of granting end users access to ready-to-use software. Rather than having to deploy, patch and update a number of apps on a variety of devices. SaaS applications are cloud based and so can be reached over the Internet using just a modern web browser. This method of accessing and using software means that potentially all required end user apps can be accessed from the same user dashboard through a browser.
SaaS examples
Examples of SaaS applications include:
- Microsoft Office365
- Google GSuite
- Salesforce
- Slack
- DocuSign
- MailChimp
- Dropbox
What is serverless computing?
First let's recap:
IaaS:
What does the vendor provide?
All of the physical and some of the core logical infrastructure such as networking.
What are the customer's responsibilities?
All VM creation, configuration and maintenance. All application installation, configuration and maintenance on the VMs. Has the greatest overhead but most control.
PaaS:
What does the vendor provide?
All of the physical and most of the logical infrastructure. Core application installation of the PaaS service (database server or webserver for example) and general maintenance.
What are the customer's responsibilities?
Configuration of service (such as adding a website or securing a database). Has far less administrative overhead than IaaS but gives limited control of the underlying resources.
SaaS:
What does the vendor provide?
All of the physical and all of the logical infrastructure. All application installation and maintenance.
What are the customer's responsibilities?
Configuring access to the application for the appropriate users. Has the least administrative overhead, however also gives the least administrative control over the underlying resources.
So what more can Serverless computing do for us?
Functions, or Serverless computing, provides a mechanism for running code separately, but in addition to, all of the above.
Why would you want to do that?
Well it's essentially a way to have essential application tasks run without having to code them in to your applications. The less monolithic code in your apps, the easier they are to maintain and develop.
For example, imagine you want to have log files collected from different application servers, compacted into a single file then output in to a storage system. You could write this code in your app but it makes the app code bulkier and harder to maintain. You could write the code to run on different VMs to separate it from your app but then you have to think about scale and availability as well as the cost of having the machine idle for large parts of the day.
With serverless computing, you could have this essential code “fired” when it is needed by using a scheduler or an action such as a simple trigger from the application itself. This way, there are no long running VMs to pay for, no clusters to manage and less monolithic application code to think about. With this, you simply fire and forget.
Serverless computing examples
Common examples of serverless computing options include:
- Google Cloud Functions
- AWS Lambda
- Azure Function
Learn about the different types of cloud computing and cloud services
If you want to learn more about cloud computing, you may be interested in attending one of our introductory or in-depth training courses, such as Google Cloud Fundamentals: Core Infrastructure.
For more information about the training we offer and the routes to Google Cloud certification, explore the full list of cloud training courses.
