The phrase Cloud
Computing is commonly used to refer to network related services which appear to
be offered by real server hardware, but these are in fact are provided by virtual hardware which simulated by
software running on one or more real machines. These virtual servers do not
exist physically and can therefore be moved around without affecting the end
user.
Cloud Computing can
be defined as “A virtualized compute power and storage delivered vis
platform-agnostic infrastructures of hardware and software accessed over the
Internet.” These on-demand IT resources
are created and disposed of sufficiently and are dynamically scalable through a
variety of programmatic interfaces. In general Cloud Computing is anything that
involves delivering services which are hosted over the Internet.
The Cloud Computing
can be broadly divided into three Categories:
·
Infrastructure-as-a-Service(IaaS)
·
Platform-as-a-Service(Paas)
·
Software-as-a-Service(SaaS)
1) Infrastructure-as-a-Service
provides a virtual server to access and
configure their virtual servers and storage.
2) Platform-as-a-Service
is defined as a set of software and product development tools which are hosted
on the provider’s infrastructure.
3) In Software-as-a-Service
the vendor supplies the hardware infrastructure, the software and interacts
with the user through a portal.
There are four
types of Clouds. They are:
Public Cloud: In the public cloud, the computing
infrastructure is hosted at the vendor’s premises. Moreover, the user has no
visibility over the location of the Infrastructure. It can be shared between
organizations.
Private Cloud: In the Private cloud, the architecture is
dedicated to the user and is not shared with other organisations. The Private
cloud can be hosted externally as well as in a premise.
Hybrid Cloud: In the
Hybrid cloud, the organisations usually host applications which are
critical and secure in private clouds. The alication which are not critical are
hosted in public cloud. This comblnation of public and private cloud is called
as Hybrid cloud.
Community Cloud: In the community cloud, the cloud is shared
between the organiations of the same community.
