Cloud computing has been revolutionizing the IT organizations with a lead to manage their information resources over a wide range of network. Although, it is very flexible, proficient and cost-effective but there are some security exploits on the other side of the coin. Cloud computing is penetrating in small scale enterprises very promptly, but still large scale enterprises feel insecure after knowing about the constraints occurring in the cloud in regard to security. In this paper, we will discuss the various cloud service providers, assets of clouds, architecture, acceptance of clouds from last 5 years and the limitations that are disrupting it to enter the organizations.