The cloud computing has reduced the performance and profitability of the materiel and software resources. These challenges were solved by several load balancing algorithms between the virtual machines of the data centers. In fact, the authors find three main points of research in this paper: data center: It receives queries from clients of cloud service to run them, using its own virtual machines in a sequential or parallel way. Sharing resources, is one of the main characteristics of the data center in the cloud computing.