Cloud service description (CSD) becomes an active area which attracts the attention of many research organizations, while no standard CSD exists. This lack of standardization is caused by the vendor lock-in problem, where cloud providers use various techniques (languages, standards, ontologies, models, etc.) to describe cloud services. Furthermore, there are few studies which dealt with the four ... [Show full abstract] aspects of service especially the technical, operational, business, and semantic aspects. Whereas, many other studies dealt only with some of these four aspects. This is the case of WSDL (Web Service Description Language) language, which focuses in the technical aspect, but it does not cover business and semantic ones. Our objective in this paper is to identify the foundations of a standardized CSD covering the technical, operational, business, and semantic aspects. We present a comparative study of the different approaches that address CSD issues. The result of this comparative study shows that USDL (Unified Service Description Language) is the appropriate language supporting a service description by covering three aspects (technical, operational, and business), despite its inability to cover the semantic aspect.