What is Cloud Computing?

Cloud computing is a topic that many find confusing. It isn’t, though, as confusing as it sounds. In fact, most of those who claim not to understand the subject are part of the majority that use it daily.

In basic terms, cloud computing is the phrase used to describe different scenarios in which computing resource is delivered as a service over a network connection (usually, this is the internet). Cloud computing is therefore a type of computing that relies on sharing a pool of physical and/or virtual resources, rather than deploying local or personal hardware and software. It is somewhat synonymous with the term ‘utility computing’ as users are able to tap into a supply of computing resource rather than manage the equipment needed to generate it themselves; much in the same way as a consumer tapping into the national electricity supply, instead of running their own generator.

One of the key characteristics of cloud computing is the flexibility that it offers and one of the ways that flexibility is offered is through scalability. This refers to the ability of a system to adapt and scale to changes in workload. Cloud technology allows for the automatic provision and deprovision of resource as and when it is necessary, thus ensuring that the level of resource available is as closely matched to current demand as possible. This is a defining characteristic that differentiates it from other computing models where resource is delivered in blocks (e.g., individual servers, downloaded software applications), usually with fixed capacities and upfront costs. With cloud computing, the end user usually pays only for the resource they use and so avoids the inefficiencies and expense of any unused capacity.

However, the advantages of cloud computing are not limited to flexibility. Enterprise can also benefit (in varying degrees) from the economies of scale created by setting up services en masse with the same computing environments, and the reliability of physically hosting services across multiple servers where individual system failures do not affect the continuity of the service.

There is also great choice in the level of security and management required in cloud deployments, with an option to suit almost any business:

A public cloud, for example, is a cloud in which services and infrastructure are hosted off-site by a cloud provider, shared across their client base and accessed by these clients via public networks such as the internet. Public clouds offer great economies of scale and redundancy but are more vulnerable than private cloud setups due their high levels of accessibility. More information can be found on our ‘What is a Public Cloud?’ page.

Private clouds on the other hand use pooled services and infrastructure stored and maintained on a private network – whether physical or virtual – accessible for only one client. The obvious benefits to this are greater levels of security and control.  Cost benefits must be sacrificed to some extent though, as the enterprise in question will have to purchase/rent and maintain all the necessary software and hardware. More information can be found on our ‘What is a Private Cloud?’ page.

Over the last few years clouds have become the buzzword in computing. But ask someone what cloud computing is and they’re likely to give you a very different answer to the person standing next to them.

Like clouds themselves, the definition of cloud computing is currently a little fuzzy.

Today cloud computing covers anything that involves delivering hosted services over the internet. These services are generally divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).

Clouds are owned by large single parties such as individual companies and are usually used by small to medium commercial businesses and researchers. These users normally pay the provider to use their computing resources.

The name cloud computing came from the cloud symbol that is frequently used to represent the Internet in diagrams and flowcharts.

All cloud services have three unique characteristics that distinguish them from traditional hosting:

    They are commercial and sold on demand to users
    They are flexible - a user can have as little or as much of the service as he wants at any time and can quickly outsource peaks of activity without long term commitment
    They are fully managed by the cloud provider; the consumer requires only a computer and internet access.