Way before the emergence of the cloud computing phenomena, there has been an insatiable demand for research from all corners of the globe. Cloud computing is considered the foundation of the next generation computing revolution, and it is quickly becoming the trendiest issue in the IT world. This rapid shift to Cloud computing has sparked worries about a crucial aspect of information systems, connectivity, virtualisation, availability of data and integrity, public auditing, scientific application, and information security. As a result, cloud computing research has received a lot of attention in recent times. This paper reviews open difficulties and issues in Cloud computing. The study is separated into three sections: first, we examined the cloud computing architecture and the various services it provides. In second section, based on its service layer, we identified numerous security vulnerabilities in cloud computing. Furthermore, from the perspective of Cloud computing adoption, we highlighted numerous open issues as well as their future consequences. Lastly, we have discussed about the platforms relevant for cloud research and development in the contemporary period.