During the last years we have seen a dramatic increase of new Cloud providers, applications, services, management platforms, data, etc. reaching a level of complexity that implies the necessity of new solutions to deal with such vast, shared and heterogeneous services and resources. Consequently, challenges often related to interoperability, portability, security, discovery, selection, negotiation and description of cloud service and resource may take place. In this sense, Semantic Web Technologies, holding a great potential to cloud computing, have been proven as an efficient means to relive these challenges. This paper examines and explores the role of Semantic Web Technologies in the cloud from a wide variety of literatures. Various approaches, architectures, and frameworks are screened and evaluated based on eight prime research questions. At the end of the review, research opportunities in the form of a roadmap are discussed