The Activation Count is a counter that is incremented every time a user activates a license, be it on the same computer or on a different computer. It does not reflect the number of systems on which a license has been activated.
An Activation Count greater than 1 does not necessarily indicate that the user has activated the license on more than one system. It typically means that the user clicked the Activate button multiple times from the same system.
The Activation Count is used when enforcing the server properties maxActivationsPerSystem and maxActivationsEnforcedOnVMsOnly properties in order to prevent a user from circumventing the license enforcement by cloning virtual machines.