“The cloud” simply refers to a collection of servers in a datacentre that is owned and managed by another organisation, that is then accessed over the internet by clients. It exists to provide infrastructure to organisations that no longer want to host physical server infrastructure within their own premises.
How does cloud computing work?
Cloud computing relies on a technology call virtualisation. This allows for the creation of a “virtual” computer that behaves exactly like a physical computer within a piece of software running on a physical machine, known as the host machine. In a datacentre with hundreds of physical servers, correctly configured virtualisation can create the virtual computer on any available physical machine that meets its requirements.
What are the different types of cloud?
- Over time, the capabilities and use of cloud computing have grown to match the ever-changing IT landscape. Currently the most common are:
- Infrastructure-as-a-Service (IaaS) – the main origin of cloud computing, where clients can move their on-premises infrastructure into a cloud environment. Examples of IaaS include Microsoft Azure, Amazon AWS, and Google GCP.
- Software-as-a-Service (SaaS) – this is where a service provider makes a piece of software available to you accessed over the internet. The service provider hosts all the infrastructure, and users just browse to a website to access the software. Examples of SaaS include Microsoft Office 365, Dropbox, and Salesforce.
- Platform-as-a-Service (PaaS) – typically used as part of a development lifecycle and provides developers with all the tools necessary to create their own software. Examples of PaaS include Heroku, Force.com, and Apache Stratos.
What are the benefits to cloud computing?
One of the biggest advantages to using cloud over on-premises infrastructure is the time and money cost savings that come from not having to purchase, install, and maintain your own infrastructure. All work associated with physical hardware is effectively outsourced to the cloud provider. Another key benefit is improved availability and resilience. Where previously an organisation might rely heavily on a single critical server in their server room, where any downtime has a significant impact on the organisation, cloud computing and virtualisation means that should a physical machine hosting virtual computers fail, the service can be moved to another device quickly and with minimal impact to end users.
