Licensing is priced in packs of 25 VMs (Virtual Machines). Editions can be used in conjunction with an existing or separately purchased vCenter Server edition. SnS is required for at least one year. The 25 VM pack can be distributed across multiple sites. A maximum of a single 25 VM pack can be used in a single remote location or branch office. - See more at: http://www.vmware.com/products/vsphere/pricing.html#sthash.dxkdB3WD.dpuf