Definition :
The Cloud computing is a model for enabling ubiquitous, convenient, on-demand
network access to a shared pool of configurable computing resources (e.g., networks,
servers, storage, applications, and services) that can be rapidly provisioned and released
with minimal management effort or service providers interaction.
Evolution of Cloud Computing
The cloud computing becomes very popular in short span of time along with delivery
of prominent and unique benefits which were never before. Therefore, it is important to
understand evaluation of cloud computing. In this section we are going to understand the
evolution of cloud computing with respect to hardware, internet, protocol, computing
and processing technologies.
Cloud Characteristics
- The NIST have defined five essential characteristics of cloud computing, which are
explained as follows. - On-demand self-service : Each consumer can separately provisioned computing capabilities like server time, compute resources, network and storage, as needed
- automatically without requiring human interaction with service provider. Broad network access : The cloud capabilities are available over the network which are provisioned through a standardize network mechanisms that are used by
- heterogeneous client’s platforms like thin or thick client, mobile phones, tablets,
laptops, and workstations.
The distributed computing turns into a priority innovation in each IT association due to its unmistakable advantages over the current processing innovations.
Distributed computing is exceptionally associated with other processing models like matrix registering, disseminated figuring and equal figuring which are combined with virtualization.
It is planned to utilize circulated equipment and programming assets which are consolidated together to accomplish higher throughput at lower cost and can ready to take care of enormous scope calculation issues in lesser time.
Fundamentally, Distributed computing has conglomeration off guring assets (like computer chip, recollections), organizing arrangements, stockpiling the board also, virtualization arrangements which are accessible on request, and conveyed monetarily.
Today, the utilization of distributed computing is huge in size since it has capacity to convey assets and administrations of any size whenever without stressing to arrangement anything at quicker rate with prudent expense.

The administrations given by cloud follows a utility-based model which brings about cost for utilized benefits just and it doesn't need to arrangement or introduceany product or equipment for the utilization. It is a conveyed registering model through
which client can get to shared pool of assets, applications and administrations from anyplace whenever on any associated gadgets. Prior, associations were utilized to keep different servers in their server rooms, where they had separate document servers to store the reports, data set servers to store the records in data sets, exchange servers to run
the exchanges, trade servers to run the Email applications and web servers for web facilitating.
The arrangement and forthright expense of each and every server was expensive as it has required very costly equipment, exorbitant server working frameworks and related application/data set programming, etc.
A side from that it moreover needs extra labor to manage it like organization head to investigate the organization, Framework director to manage the equipment, Data set executives to manage the data sets, Web chairman to manage the sites, etc. Hence, capital cost related with the previous plans was unnecessarily high and was not sensible for little and medium-size associations. As such, to ask about on standard plans delivered distributed computing.
Advantages of Cloud Computing
There are many advantages of cloud computing, some of them are explained as
follows.
Improved accessibility : The cloud computing provides efficient access to services
and resources from anywhere, at any time, on any device.
Optimum Resource Utilization : Servers, storage and network resources are better
utilized in the cloud environment as they are shared among multiple users, thus it
cut down the wastage of resources.
Scalability and Speed : The cloud computing provides high scalability where
capacity of hardware, software or network resources can be easily increased or
decreased based on demand. In this, organizations do not have to invest money and
time behind buying and setting up the hardware, software and other resources
instead, they can easily scale up or scale down their resources or services running
on cloud as per demand with the rapid speed of access.
Minimizes licensing Cost of the Softwares : The remote delivery of software
applications saves licensing cost such that users do not need to buy or renew
expensive software licenses or programs.
Less personnel training : The users of cloud do not need any personal training to
deploy or access the cloud services as the self-service portals of cloud used to have
user friendly GUIs where anyone can work with cloud services easily.
Flexibility of work practices : Cloud computing provides freedom of access to their
users such that the employees can work more flexibly in their work practices. The
flexibility of access to the cloud data allow employees to work from home or on
holiday through internet.
Sharing of resources and costs : The cloud computing fulfills the requirement of
users to access resources through a shared pool which can be scaled easily and
rapidly to any size. The sharing of resources saves huge cost and makes efficient
utilization of the infrastructure.
Minimize spending on technology infrastructure : As public cloud services are
readily available, the Pay as you go or subscription based utility feature of cloud
allows you to access the cloud services economically at cheaper rate. Therefore, it
reduces the spending on in-house infrastructure.
Maintenance is easier : As cloud computing services are provided by service
provider through internet, the maintenance of services is easier and managed by
cloud service providers itself.
Less Capital Expenditure : There is no need to spend big money on hardware,
software or licensing fees so capital expenditure is very less.
On-demand self-service : The cloud provides automated provisioning of services
on demand through self-service websites called portals.
Broad network access : The cloud services and resources are provided through a
location independent broad network using standardized methods.
Resource pooling : The cloud service provider adds resources together into a
resource pool through which user can fulfill their requirements and pool can be
made easily available for multitenant environment.
Measured services : The usage of cloud services can be easily measured using
different measuring tools to generate a utility-based bill. Some of the tools can be
used to generate a report of usage, audit and monitored services.
Rapid elasticity : The cloud services can be easily, elastically and rapidly
provisioned and released through a self-service portal.
Cloud Computing 1 - 9 Introduction
TECHNICAL PUBLICATIONS® - An up thrust for knowledge
Server Consolidation : The server consolidation in cloud computing uses an
effective approach to maximize the resource utilization with minimizing the energy
consumption in a cloud computing environment. The virtualization technology
provides the feature of server consolidation in cloud computing.
Multi-tenancy : A multi-tenancy in cloud computing architecture allows customers
to share same computing resources in different environment. Each tenant's data is
isolated and remains invisible to other tenants. It provides individualized space to
the users for storing their projects and data.