KMS (Key Management Service) and MAK (Multiple Activation Key) are both methods for activating Microsoft volume license software, but they serve different purposes and are used in different scenarios. KMS is designed for organizations with multiple computers that need to be activated within a local network. It requires a KMS server to be set up and provides activation services for devices connected to the network. MAK, on the other hand, is used for activating individual installations with a limited number of activations per key. MAK is typically used for standalone or remote installations where KMS is not feasible. The choice between KMS and MAK depends on your organization’s specific needs and infrastructure setup.