VMware vSphere vs VirtualBox

VMware vSphere
Build your own cloud infrastructure in your datacenter and remote sites on VMware vSphere the world’s leading server virtualization platform. Virtualize your x86 server resources and aggregate them into logical pools for allocation of multiple workloads. Get network services optimized for the virtual environment, along with simplified administration and management. Reduce the complexity of back-end storage systems and enable the most efficient storage utilization in cloud infrastructures.
Oracle VirtualBox is a powerful virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2. See "About VirtualBox" for an introduction.