Cloud computing involves delivering hosted services over the Internet. Cloud computing enables companies to consume computer resources as a utility — just like electricity — rather than having to build and maintain computing infrastructures in-house. These services are broadly divided into three categories: Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) and Infrastructure-as-a-Service (IaaS).

There are a number of options available to organisations to utilise cloud services and these are typically:

  • Self-service provisioning: End users can spin up computing resources for almost any type of workload on-demand.
  • Elasticity: Companies can scale up as computing needs increase and then scale down again as demands decrease.
  • Pay per use: Computing resources are measured at a granular level, allowing users to pay only for the resources and workloads they use.

Cloud computing services can be private, public or hybrid.

SaaS Software as a Service

Software as a Service provides all the functions of an application and software products through a Web browser. SaaS eliminates worries about application servers, storage, application development and managing IT. Services can be anything from Web-based email such as Microsofts Live/Hotmail platform, Office 365 to CRM solutions such as The service provider such as Telstra hosts both the application and the data, this enables the organisation and its employees to access and use the service from anywhere where they have access to the internet.

PaaS Platform as a Service

Platform as a Service provides the infrastructure on virtualized servers. This gives organisations the ability to run new or existing applications from anywhere without the need of maintaining the operating systems, server hardware or computing capacity. An example of some PaaS service providers are Microsoft’s 365 and GoogleApps.

IaaS Infrastructure as a Service

Infrastructure as a Service provides clusters, like electricity grids for virtual servers, networks, storage and systems software designed to supplement or replace the functions of an entire data centre. High profile IaaS, include Amazon’s Elastic Compute Cloud [EC2] and Simple Storage Service.

Cloud computing can be scaled to match any organization need. It’s elastic, as user can have as much or as little of a service as they want and only pay for the serviced used.

Cloud computing can be private or public.

Public Cloud Computing

Public cloud gives agility by re-provision technological infrastructure, like applications and storage, on a pay-per-usage model.

Public Clouds eliminates the Capital Expense, with pay-as-you-go pricing, reducing upfront capital outlays on hardware, software and IT staff. This allows the CIO to leverage cloud resources, leaving only elastic operational IT expenses on the balance sheet.

Public Cloud services offers speed of implementation. If your business needs a quick deployment of days to weeks rather than, weeks to months, then public cloud is your best option. This gives organisations the ability to cover a spike in demand by adding more computing power as needed.

The main benefits of using a public cloud service are:

  • Easy and inexpensive set-up because hardware, application and bandwidth costs are covered by the provider
  • Scalability, providing extra compute, storage or development capacity when needed
  • No wasted resources because you pay for what you use
  • It’s elastic, because organisations can use as much or as little of a service as needed
  • The computer infrastructures is fully managed by public cloud service provider
  • A hassle free way of providing solution when an outdated software needs refreshing


There’s an increasing number of software companies, like Microsoft, Oracle, providing cloud infrastructures with their propriety software.

Private Cloud Computing

With Public Cloud Computing, organisations don’t own the computer infrastructure. So if they need to maintain control over their data, then they should look at cloud computing on private networks.

A private cloud, refers to the privately-held, proprietary network or data centre using cloud computing infrastructure, with similar capabilities as the cloud, to a limited number of people behind a firewall.

The downside of Private Cloud Computing, the users still need to buy, build, and manage the computer infrastructure eliminating many of the cost-benefits of cloud computing.

Hybrid Cloud Computing

Some organisations want to protect their sensitive information, but not all their data needs to be bullet proof. So Hybrid Cloud Computing provides the best of both worlds, while keeping their sensitive information on a private cloud, and everything else in a public cloud.

Hybrid Cloud Computing gets the cost-saving associated with public clouds, with most of processing and data storage transacted on a public cloud, & the data needing security done in a private cloud. An example of public cloud is Amazon’s EC2.