What is KMS?
KMS, or Key Management Services, is the deprecated method to activate licenses within an environment. A KMS server is deployed and then configured for each product that needs to be licensed (i.e Server, Office, Windows 10 etc). Then, for each product, a public KMS key is used to tell that product to activate against the KMS server in the environment. KMS is ideal for large or isolated environments that may have issues activating products with MAKs (multiple activation keys).
What is AD Based Activation?
AD Based Activation was introduced with Server 2016 and represents the next generation of KMS. One shortcoming of KMS is that it was installed on a single server and thus was a single point of failure. AD Based Activation serves the same purpose as KMS but instead, it stores it’s activation information within AD and replicates it to all other DCs thus eliminating the single point of failure. The one catch to the AD Based Activation is that it can only be used to activate software for the following products:
- Server 2016+
- Windows 10+
- Office 2016+
If you need to activate older versions of these products then you need to use KMS to do so.