A Review Paper on Evolution of Cloud Computing, its Approaches and Comparison with Grid Computing Rajleen Kaur, Amanpreet Kaur M.Tech CSE, Global Institute of management and Technology, Amritsar Abstract--Cloud computing has become an interesting topic among the IT industry, Business Intelligence and users. Cloud computing is an internet based computing which has powerful computational architecture and it offers universal services to the customers and it has several benefits over grid and other computing. It is not a location depending computing in which shared servers provides all the data, software and services to computer and some other required devices like mobile phones, PDA’s etc. In this paper, we have given a review on evolution of cloud computing, its comparison with grid computing and various approaches to cloud computing. Keywords-- Cloud, SaaS, PaaS, IaaS, Cloud Computing, Grid Computing I. INTRODUCTION The term “cloud” means network of providing resources over the internet. The resources present in cloud can be used infinitely by user whenever needed. In cloud computing, customers usually preferred to third party provider for service of internet instead of setup their own physical infrastructure. Users use the resources as a service and they had to pay only for that part they had used. In cloud computing, workload is shifted so that workload can be reduced. For running applications, the local computers need not to take the heavy load. Actually the load is handled by networks of computer which forms the cloud. So, on user side the demand of hardware and software reduces. So, the required thing which needs to seen the cloud computing software on computer is only web browser, like opera, Google chrome, Mozilla Firefox etc. Features of cloud computing include on demand self services, measure services, broad network area, rapid elasticity, reduce pooling, multi-tenacity and shared infrastructure. Cloud computing provides three different approaches. These are 1) Software as a Service (SaaS) 2) Platform as a Service (PaaS) and 3) Infrastructure as a Service (IaaS). Customers such as general public have also readily embraced cloud computing in the form of services like Gmail, Face book, YouTube, yahoo, hotmail etc. it provides Reduction in management responsibilities and then our main concern is on production and innovation. It is more increasingly used in business which meets the need of changing environment. Fig 1.1: Many companies deliver services from the cloud and they are Google, Microsoft and SalesForce.com, Amazon, Yahoo etc [5] II. EVOLUTION OF CLOUD COMPUTING It is contribution of some scientific research to develop a definition of the cloud computing and Youseff et al. were among the first person to provide understanding of cloud computing and its components. They said that cloud computing is a “combination of some new and all old concepts in a lot research fields like Service-Oriented Architectures, grid and distributed computing and also virtualization. According to Youseff et al. “cloud computing can be considered a new computing paradigm that allows users to temporary utilize computing infrastructure over the network, supplied as a service by the cloud-provider at possibly one or more levels of abstraction” (Youseff et al. 2008). According to Armbrust et al. “Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS). The datacenter hardware and software is what we will call a Cloud. When a Cloud is made available in a pay-as-you-go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing. We use the term Private Cloud to refer to internal datacenters of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not include Private Clouds” (Armbrust et al. 2009). Rajleen Kaur et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 5 (5) , 2014, 6060-6063 www.ijcsit.com 6060