Microsoft is just one company using CALs to ensure proper usage of its systems and applications. Whether or not multiple CALs will be necessitated, or single CALs are used, is primarily based on whether a product is being used for personal or business use. For business use, CALs may be assigned to more than one person, but multiple users may not use the software simultaneously. Larger organizations generally benefit from device CALs, which may be applied to all devices or computers connected to a shared server.