Cloud computing is, simply put, using information technology as a service over the network. These services could relate to computing – for example, running complex calculations on multiple rented powerful servers on the network – or storage – for example, storing the results of the calculations on a virtual server and accessing it whenever necessary.  This system also has the ability to scale dynamically as needed. You may start a new service, giving you new clients and 10 times your existing documentation, and you would still be able to store them on the Cloud without having to spend a lot of money.

Cloud computing can reduce the cost of delivery of services, while increasing the speed and agility with which services are deployed. It incorporates virtualization, on-demand deployment, Internet delivery of services, and open source software. The self-service nature of cloud computing can enable companies, especially small ones without the resources of their larger counterparts, create elastic environments that can contract or expand based on need.  Its pay-by-use nature means that companies do not have to shell out large amounts of money for something that they cannot make full use of. So, basically, you can build applications, test them, and deploy them on a virtual machine, increasing your use of the cloud resources based on need.

Open source software plays an important part in cloud computing by allowing its basic elements to be created with easily and freely available components.

There are primarily two types of clouds:

Public Clouds: These are run by third parties and applications from different customers will be mixed together, although with security and data locality aspects in place, this should be transparent to the end user. Larger portions of the cloud can also be let out to individual customers as virtual datacenters. This gives customer greater visibility into its infrastructure, and greater manipulative capacity.

Private Clouds: These are built for the exclusive use of one customer, providing utmost control over data, security and quality of service. These can be managed either by a company’s IT organization or by a third party provider.

A third type, the Hybrid Cloud,  is a mixture of these two models, primarily by augmenting a private cloud with the resources of a public cloud.

Cloud computing makes use of three basic service models:

Software as a Service (SaaS): Software as a service features a complete application offered as a service on demand. A single instance of the software runs on the cloud and services multiple end users or client organizations.

Platform as a Service (PaaS): Platform as a service encapsulates a layer of software and provides it as a service that can be used to build higher-level services. (e.g.: Google Apps engine)

Infrastructure as a Service (IaaS): Infrastructure as a service delivers basic storage and compute capabilities as standardized services over the network. Servers, storage systems, switches, routers, and other systems are pooled and made available to handle workloads that range from application components to high-performance computing applications.

The benefits of cloud computing are many. Some of them are:

Reduce run time and response time – use multiple servers instead of just one to run your calculations

Minimize infrastructure risk – you own lesser infrastructure

Lower cost of entry – infrastructure is rented, and applications are ‘assembled’

Increased pace of innovation – deploy quickly and at low cost, freeing resources

So, cloud computing is available, scalable, flexible, reliable, secure and efficient. Do you want more reasons to start evaluating your existing infrastructure?

Source: Introduction to Cloud Computing Architecture, White Paper, Sun Microsystems, 1st Edition, June 2009