As cloud computing industry is advancing toward an era where resources are delivered as a service rather than a product. It provides infrastructure, software, application, platform, data and resources as a service over the internet with on-demand and pay-per-use model. Clouds are used for hosting a large range of services. These services between different Cloud Service Providers (CSPs), has different pricing model and the cost of individual resources are very different. Heterogeneity among different cloud providers causes many problems like vendor lock-in.