CLOUD COMPUTING

       
             Now into fourth topic I now want to concentrate more on topics which while giving seminars or presentation we try mugging up some part of the article so that we can say our part of article comfortably in front of our judges but in actual when we try to recall what we had learned for our presentation and apply it in our real life we just can't recall even the basic concept in it at that particular time but we had given proper presentation to our judges by seeing the slides in the powerpoint file sometimes or by recalling the things we had mugged up previously for our presentations,but with my own personal experience i can guarantee it to you that the topics you had mugged up previously will be of no use to you in future or at times when you have that topic in your syllabus in future you would simply feel like learning it for first time.
          so after this experience I felt the need to write about the technologies which are commonly given to students for presentation purpose and i want you to learn this thing in our own way and not in the way wikipedia has information in it i.e. it might be having lot of data but the language used are highly technical and always takes more time in understanding the topic properly . so that it might be useful to someone in future.
so today our topic is " CLOUD COMPUTING " -Cloud computing is a model for enabling 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 provider interaction.
         Traditionally, without a cloud, a web server runs as a single computer or a group of privately owned computers. The computer(s) are powerful enough to serve a given amount of requests per minute and can do so with a certain amount of latency per request. If the computer's website or web application suddenly becomes more popular, and the amount of requests are far more than the web server can handle, the response time of the requested pages will be increased due to overloading. On the other hand, in times of low load much of the capacity will go unused. but now with the help of cloud computing the given website is stored on the cloud with thousands of other website in the cloud so whenever demand or popularity for particular website increases the cloud can automatically direct more individual computers to work to serve pages for the site, and more money is paid for the extra usage. and if the demand is decreased the amount of money due will be less. Cloud computing is popular for its pay-as-you-go pricing model.Clouds are sometimes set up within large corporations, or other institutions, so that many users all share the same server power.
             As computer power gets cheaper, many different applications are provided and managed by the cloud server. In many cases, users might not download and install applications on their own device or computer; all processing and storage is maintained by the cloud server. The phrase "software as a service" (SaaS) is sometimes used to describe application programs offered through cloud computing. A common shorthand for a provided cloud computing service (or even an aggregation of all existing cloud services) is "The Cloud".
              Any computer or web-friendly device connected to the Internet may access the same pool of computing power, applications, and files in a cloud-computing environment. Users may remotely store and access personal files such as music, pictures, videos, and bookmarks; play games; or do word processing on a remote server. Data is centrally stored, so the user does not need to carry a storage medium such as a DVD or thumb drive. Desktop applications that connect to internet-host email providers may be considered cloud applications, including web-based Gmail, Hotmail, or Yahoo! email services.

Essential Characteristics:

On-demand self-service -- A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.

Broad network access -- Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling -- The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, network bandwidth, and virtual machines.

Rapid elasticity -- Capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.

Measured Service -- Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service.

some people may describe cloud computing in any ways given below:-

Some say it's because the computer functionality happens out there "in the clouds."

most technology diagrams depict the Internet or IP availability by using a drawing of a cloud

         
          Not only is cloud computing a speedier way of getting IT together, it's more cost-efficient, too. As the W. P. Carey School's Demirkan says, similar to electricity, computing power is also "perishable and intangible." According to him, "If you buy a server and it's been running all day but you didn't use it, you can't store a computer system's capacity and use it later." It's a waste, but that is what happens when companies purchase their own IT infrastructure and don't operate it 24/7 with 100 percent utilization. "With cloud computing, companies don't have those set-up costs, and they don't have idle hours" wasting their IT resources.
       In addition to infrastructure resources (i.e. hardware, software, power, space), those resources include the people who manage the systems, as well as the IT security. "With cloud computing, a company's IT operation costs will go down significantly," Demirkan notes.
      now going to its working,A cloud user needs a client device such as a laptop or desktop computer, pad computer, smart phone, or other computing resource with a web browser (or other approved access route) to access a cloud system via the World Wide Web. Typically the user will log into the cloud at a service provider or private company, such as their employer. Cloud computing works on a client-server basis, using web browser protocols. The cloud provides server-based applications and all data services to the user, with output displayed on the client device. If the user wishes to create a document using a word processor, for example, the cloud provides a suitable application running on the server which displays work done by the user on the client web browser display. Memory allocated to the client system's web browser is used to make the application data appear on the client system display, but all computations and changes are recorded by the server, and final results including files created or altered are permanently stored on the cloud servers. Performance of the cloud application is dependent upon the network access, speed and reliability as well as the processing speed of the client device.
         Cloud architecture,the systems architecture of the software systems involved in the delivery of cloud computing, typically involves multiple cloud components communicating with each other. The two most significant components of cloud computing architecture are known as the front end and the back end. The front end is the part seen by the client, i.e., the computer user. This includes the client’s network (or computer) and the applications used to access the cloud via a user interface such as a web browser. The back end of the cloud computing architecture is the cloud itself, comprising various computers, servers and data storage devices.

           
     now without increasing the size of the blog i will give you name of the layers used in cloud computing:-

1)Provider

2)Client

3)Application

4)Platform

5)Infrastructure

6)Server

           I hope this post would have helped you to some extent,as topic was on technology reference was taken from wikipedia, thank you friends for your feedback on previous topics,and hope you give feedback on this topic as well.