You probably heard this word a lot, since you can't escape from
From data-processing press to big software companies, everyone is
talking about it. But questions remains.
What does it mean? Where is it located? What are its benefits? We
shall try to answer those questions.
Definition of cloud computing
Cloud computing is a model allowing an omnipresent practical access
to both a shared network and a set of available resources (such as :
networks, servers, storages, software and services). Which can be funded
and released with a minimum of administration.
An example to better understand
Before the cloud, to store and watch your photos you
The photographs are not stored on your premise, they are on
computers which are made safe and saved: you cannot lose them.
You rent the disk space necessary. When you do not have any
more, you rent larger.
You are not likely to lose your photographs because of a device
failure (hard drive breakdown), it is the cloud who manages the
You have access to it, from anywhere as long as you have an
The cloud offers more than just
For most, the cloud is summarized by an online storage of document
services (Hubic, Drop Box, Google Drive...), but the cloud is much more
You can find Office like editing software, image processing,
drawings software and many more. Such as Google WebApps, Microsoft azure
and many more.
Characteristics of the cloud computing
On demand self-service.
Broad network access.
Three service models:
Use a software, like a service.
You don't need to install the software you want to use on your
computer, but use it remotely instead. The software take turns on the
waiters in datacenters.
Most of the time, this software is used via a Web browser.
SaaS examples: Google Apps and
Use an infrastructure, like a service.
You don't need to buy a set of equipment to install your
You are satisfied to rent this equipment as if it belonged to you.
You install the waiters which you wish to use.
You manage the whole of OS installed on the waiters which you
The companies often use IaaS, because they can have a large set of
last generation waiters available ready and quickly available.
IaaS examples: HP
Adaptive, Rackspace and Amazon E2C
Use a platform, like a service.
You rent an entire platform, meaning a machine with a ready to go
Operating System, which typically includes programming language, execution
environment, database and web server.
Pass examples: Salesforces.com, Microsoft Azure
and Amazon E2C.
If by any bad luck, your electronic device and associated hard
drive happened to break down, you were then unable to take a look to
your photos, and maybe even losing them forever.
Your hard drive must have a sufficient capacity to store all
your photos, if you lack any space, you will have to buy a new hard
drive, and maybe even a new computer.
You can look at your photographs ONLY on your computer (except
if you shared the files containing the photographs).
With the cloud, to store and watch your photos, you now
An Internet connection (computer, laptop, smart TV, smartphone…)
is now enough to look at your photographs.
Private Cloud : The whole of the
resources is affected only with only one organization or company.
Community Cloud : The whole of the
resources comes from several organizations or companies which share
Public Cloud : The resources are
put at disposal of everyone.
Hybrid Cloud : It is about mixed
one between deprived and the public.