In the simplest term cloud computing means storing and accessing data over the internet instead of using the computer’s hardware. Cloud computing is a type of internet-based computing which provide us shared processing resources and data to the system and other devices according to the demand of the user. Cloud computing can be used everywhere in today’s life. Cloud computing security is broad research with various concerns, starting from protecting the hardware and platform technologies to protecting clouds data and resource access (through different end-user devices). Although there are n numbers of advantages of using cloud computing and all of them are tremendous, but the security and privacy concern of cloud computing has always been the main concern of numerous cloud customers and an impediment to its widespread adaptation by business and organization. The paper presents a review in the field of cloud computing with a focus on risk assessment.