Volunteer Computing is one of the distributed computing that computes the task in the spare resources provided by the volunteer devices. Volunteer Computing is also referred to as peer-to-peer computing and global computing. It offers an alternative infrastructure for computation with cost and energy efficiency to overcome the shortcomings in the centralized environment and expensive data centers. In Volunteer Computing, any users act as volunteers to donate their idle computing resources of devices including desktop computers and routers to the users having the computational and storage-intensive tasks such as big data analysis and scientific research works. Volunteer cloud computing has emerged in different areas. For example, users of a social network share their heterogeneous computing resources in the form of an Adhoc cloud, which is referred to as social cloud computing. The deliverables in Volunteer Computing are an unidentifiable part of processing scientific researches. Volunteer computing performs its computation as a background process compared to the foreground process of other community-based systems requiring interactions. The challenges that need to be overcome by the researches on volunteer cloud computing. • Minimizing the overheads in a highly virtualized environment is essential due to the heterogeneous hardware devices and ad-hoc nature. • It is necessary to address the security and privacy concerns to boost the confidence among the public while accessing the resources from the volunteers. • Modeling a consistent platform is essential for volunteer computing with the integration of the social networks and cloud. • Scientific applications dominate volunteer computing and only a very small fraction of the potential volunteer nodes have the ability to provide resources for scientific applications. • Combining the users in volunteer cloud computing is one of the challenging tasks. It is necessary to design new techniques for utilizing the full potential of Volunteer Computing. • Moreover, utilizing the volunteer host for reliable cloud services is one of the critical constraints since the resources in volunteer computing are volatile in nature.