Grid Computing Vs Cloud Computing

GRID COMPUTING    Grid computing is the act of sharing tasks over multiple computers. Tasks can range from data storage to complex calculations and can be spread over large geographical distances. In some cases, computers within a grid are used normally and only act as part of the grid when they are not in use. These grids scavenge unused cycles on any computer that they can access, to complete given projects.  xyxabc@home is perhaps one of the best-known grid computing projects, and a number of other organizations rely on volunteers offering to add their computers to a grid.     These computers join together to create a virtual super computer. Networked computers can work on the same problems, traditionally reserved for supercomputers, and yet this network of computers are more powerful than the super computers built in the seventies and eighties. Modern supercomputers are built on the principles of grid computing, incorporating many smaller computers into a larger whole. The idea of grid computing originated with Ian Foster, Carl Kesselman and Steve Tuecke. They got together to develop a toolkit to handle computation management, data movement, storage management and other infrastructure that could handle large grids without restricting themselves to specific hardware and requirements. The technique is also exceptionally flexible. Grid computing techniques can be used to create very different types of grids, adding flexibility as well as power by using the resources of multiple machines. An equipment grid will use a grid to control a piece of equipment, such as a telescope, as well as analyze the data that equipment collects. A data grid, however, will primarily manage large amounts of information, allowing users to share access Grid computing is similar to  cluster computing, but there are a number of distinct differences. In a grid, there is no centralized management; computers in the grid are independently controlled, and can perform tasks unrelated to the grid at the operator's discretion. The computers in a grid are not required to have the same operating system or hardware. Grids are also usually loosely connected, often in a decentralized network, rather than contained in a single location, as computers in a cluster often are.  CLOUD COMPUTING   Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams. A cloud service has three distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing. A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services. Infrastructure-as-a-Service like Amazon Web Services provides virtual server instanceAPI) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required. Because this pay-for-what-you-use model resembles the way electricity, fuel and water are consumed, it's sometimes referred to as utility computing. Platform-as-a-service in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure. Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs, website portals or gateway software installed on the customer's computer. Force.com, (an outgrowth of Salesforce.com) and GoogleApps are examples of PaaS. Developers need to know that currently, there are not standards for interoperability or data portability in the cloud. Some providers will not allow software created by their customers to be moved off the provider's platform. In the software-as-a-service cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front-end portal. SaaS is a very broad market. Services can be anything from Web-based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.