Into the Clouds - Part 1 - what is cloud computing ?

My Burning Question:

What exactly is Cloud Computing ?

The IT industry is reknowned for creating buzzwords and then using them everywhere.  The world “cloud” is like that. It’s use is varied and is sometimes inaccurate.   So I thought I’d learn more specifics about it.  I went to my best friend “Google” and typed in “define cloud” and promptly learnt all about clouds ! Did you know the clouds above the earth are based on 10 main groups ?

Cirrus, Cirrocumulus, Cirrostratus, Altocumulus, 
Altostratus, Nimbostratus, Stratocumulus, Stratus, Cumulus, Cumulonimbus.

These in turn are each sub divided into 3 levels ?  All have different characteristics, properties with varying results (eg rain, thunder etc).  [Info : Met Office]  

So, I realised 2 things:

1. Remember to be very specific when Googling.
2. If the clouds above are not that simple it’s likely that the IT “Cloud Computing” will also be somewhat complex with lots of varieties too.

In September 2011 the NIST (National Institute of Standards and Technology) http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf defined Cloud Computing as: 

“Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (eg networks, servers, storage, applications and services) that can be rapidly provisioned an released with minimal management effort or service provider interaction.  This cloud model is composed of 5 essential characteristics, three service models and four deployment models.”

5 essential characteristics:

1. On-demand self-service
2. Broad network access
3. Resource pooling
4. Rapid elasticity
5. Measured Service

3 Service Models:

1. Software as a Service (SaaS)
2. Platform as a Service (PaaS)
3. Infrastructure as a Services (IaaS)

4 Deployment Models:

1. Private cloud – provisioned by a single organisation comprising multiple consumers.  This can exist on or off premises.
2. Community Cloud – provisioned for exclusive use by a specific community of consumers with shared concerns (eg mission, security requirements, policy and compliance considerations).
3. Public Cloud – provisioned for open use by the general public.  This will exist on the premises of the cloud provider.
4. Hybrid Cloud – a composition of 2 or more distinct cloud infra-structures that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability.

I’m delighted to realise that I was not having "a blonde moment" - the phrase 'the cloud' is used to define more than just one kind of solution.

My next burning question:

Which cloud suits which situation ?

Click here if you wish to read an article on Pros / Cons of Cloud Storage.