Abstract
The requisition of cloud is increasing at a high rate because of its enormous benefits such as on demand access, pay as you use,and lower upfront cost. Due to huge demand of cloud based services, the number of cloud service providers(CSPs) is also increasing rapidly.To make more money the CSPs exaggerates with the Quality of service (QoS) of their services as mentioned in service level agreement (SLA).The confusion arises for the service user (SU) in the selection of CSP. Thus, selecting a trustworthy CSP is a bigger challenge for the serviceusers (SUs). Security is also a major concern. To overcome all these problems there is a need of defining reputation system for identifyingthe trusted cloud service provider. Because of this reason resource management and reputation management is addressed individually andjointly in previous research work where resource management handles the load and reputation management helps in selecting thetrustworthy service provider. In this paper, we have discussed various reputation modals and their efficiency.