A group of interconnected servers with the responsibility of delivering resources to the end users by following 'Pay-as-you-use 'model constitutes a cloud system. As the cloud system grows, work load handled at the servers (or hosts) increases drastically. There should have a proper load balancing methods so that work load generated by the clients can be distributed smoothly across all servers. Load balancing across all servers is maintained by virtual machine migration. Cloud providers have to ensure the fast execution of jobs by implementing the methods of load balancing and thereby achieving quick response of submitted tasks and maximal utilization of hosted resources.