Volume licensing emerged in the 1990s to help large organizations deploy software across thousands of machines efficiently. Under programs like Microsoft’s Volume Licensing Service Center (VLSC), companies receive a single Master Product Key and access to downloadable ISOs—such as the one named above. However, these ISOs lack built-in activation barriers; they rely on a separate Key Management Service (KMS) or Multiple Activation Key (MAK) to activate.
The "Professional Plus" edition of Office 2016 is a comprehensive suite designed for business and enterprise environments. It includes core productivity tools—such as Word, Excel, and PowerPoint—alongside advanced applications like Outlook, Publisher, Access, and Skype for Business. The "W64" in the filename indicates it is specifically optimized for 64-bit Windows architectures