Cloud computing has emerged as the next big technological breakthrough in the field of computing. In this paper we provide an overview of cloud computing so that the importance of the brand new technology is properly understood. We first discuss the prevalent concepts of cloud computing. We then try to discuss the services of the cloud and its types in order to provide a clearer picture of cloud computing. Then we discuss certain parameters that are essential components of cloud computing and without which a service could not be considered cloud oriented. This way we eventually explain cloud computing in great detail and provide an adequate review of its characteristics and services so that the whole concept of cloud computing is better understood. Cloud computing has been ironically associated with having a cloud of confusion over its true meaning and the common user is often found wanting when it comes to the meaning of the technology itself. This paper helps the reader to understand the whole cloud computing arena, explaining all its major components in detail.