Basic Cloud Computing Overview
What is Cloud Computing?
Cloud Computing describes a scenario whereby computing resource is delivered as a service over a network connection, usually the internet.
Cloud computing 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.
Types of Cloud Computing
There are 3 fundamental deployment models of cloud computing; public cloud, private cloud and hybrid cloud.
Public Cloud
A public cloud is where 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.
Private Cloud
Private clouds use pooled services and infrastructure stored and maintained on a private network – whether physical or virtual – accessible by 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.
Hybrid Cloud
As the name suggests, a hybrid cloud combines both public and private cloud elements. A hybrid cloud allows a company to maximise their efficiencies; by utilising the public cloud for non-sensitive operations while using a private setup for sensitive or mission critical operations, companies can ensure that their computing setup is ideal without paying any more than is necessary.
Models of Cloud Computing
Broadly speaking, there are 3 models of cloud computing which describe the service on offer; these are Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS).
Infrastructure as a Service (IaaS)
As with the other cloud computing categories, IaaS refers to the delivery of virtualised computing resource as a service across a network connection. IaaS specifically deals with hardware – or computing infrastructure - delivered as a service. Offerings include virtualised server space, storage space, network connections and IP addresses. The resource is pulled from a pool of servers distributed across data centres under the provider’s control, the user is then granted access to this resource in order to build their own IT platforms. IaaS can provide enterprises with great business benefits.
Platform as a Service (PaaS)
PaaS is an extension of IaaS and describes a category of cloud computing that provides developers with environments in which to build applications over the internet. In addition to the fundamental computing resource supplied by the hardware in an IaaS offering, PaaS models also include the software and configuration (often known as the solution stack) required to create the platform on which clients can create their applications. PaaS packages can be tailored to meet individual user needs; they can cherry pick the features of the service that are relevant to them while disregarding those that are not. PaaS provides a number of benefits to enterprises, including simplifying the development process for geographically split development teams.
Software as a Service (SaaS)
SaaS is arguably the most common of the cloud computing variations; it’s the term used to describe a software delivery model in which applications are hosted (usually by a provider) and made available to customers over a network connection. Many people make use of SaaS without realising it as many web applications are delivered in this way.
Benefits
- Scalable : Automatic increase and decrease of resource as and when it is necessary, thus ensuring the level of resource is matched to demand
- Cost Effective : Users only pay for the resource they use, therefore avoiding inefficiencies and expense of any unused capacity
- Economies of Scale : Several services can be set up using the same computing resource
- Reliability : Services are hosted across multiple servers so individual system failures do not affect the continuity of the service
- Flexibility : Great choice in the level of security and management, with an option to suit almost any business