Microsoft Volume Licensing Reference Guide
Microsoft® Volume Licensing program models address organizations in two main categories: organizations with more than five but less than 250 computers and organizations with more than 250 computers.
For organizations with less than 250 computers, Microsoft Open programs provide three purchasing license options: Open Value, Open Value Subscription and Open License.
For organizations with 250 or more desktop PCs, Microsoft offers four options: Enterprise Agreement, Enterprise Subscription Agreement, Select Plus and Select License.
With some Microsoft Volume Licensing programs, you can also purchase Microsoft Software Assurance, which helps improve productivity from IT by providing new product versions, enterprise technologies, and deployment planning, training and support in one cost-effective program.