Basically it is an approach described as decoupling and migrating a server’s operating system and data from a physical server to a virtual machine guest hosted on a virtualized platform (or the cloud). It is called as one of the best features of server virtualization is the ability to migrate physical server workloads to virtual servers.
The physical to virtual migration choice allows you to remove aging servers, thus deducting the number of physical servers needed in a data center. Firstly, a physical server must be virtualized and then migrated into the cloud. Once you’ve virtualized, you will have to repeat the steps to migrate the server into a cloud. The first step while starting with a physical-to-cloud migration is to identify the tools that you will use to execute your migration and the system you want to migrate. The key point here is that you don’t have to migrate twice SaaS automatically virtualizes a physical server during the conversion process of migrating the physical server into the target cloud.