Cloud computing is a promising technology of the present and the future which uses the grid computing as its backbone. Cloud computing is the hottest topic of Information and Communication Technology (ICT) for implementing it for individual, communities and business. It provides services such as Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). It provides many benefits like scalability and pay per use, etc. Different deployment models are also available to fulfill the needs of the business and industry.