There is a third model for completing volume activation called Active Directory-Based activation.
The type of key entered in the product determines the activation method. Customers can use either or both activation methods in their environment. MAK activates systems on a one-time basis, using Microsoft's hosted activation services.
KMS allows organizations to activate systems within their own network. Volume Activation provides two different models for completing volume activations: Key Management Service (KMS) and Multiple Activation Key (MAK). Volume Activation applies to systems that are covered under a Volume Licensing program and is used strictly as a tool for activation it is in no way tied to license invoicing or billing.
It enables Volume Licensing customers to automate the activation process in a way that is transparent to end users. Volume Activation is a product activation technology used to activate Windows Vista, Windows Server 2008, Windows Server 2008 R2, Windows 7, Office 2010, Windows 8.1, Windows Server 2012 R2, Windows Server 2012 R2 for Embedded Systems, and Office 2013.
