Virtualization is an emerging technology which provides organizations with a wide range of benefits. But unluckily, from a security standpoint, functionality often takes precedence over a main area like security, leaving security to be retrofitted in later. This paper mainly emphasizes on several security threats that exists today in a virtualization environment. However, the main contribution of the paper lies in highlighting the notable types of virtualization, its security threats and hypervisor deployment models. To start with, the authors will further their understanding of the state of knowledge for the latest virtualization technology, the role of the hypervisor and the two different types of virtualization architectures.