Typically one Serial Number is valid for one PC, so that each PC has its own Serial Number. It is possible to hand out one single Serial Number to a company or offer a family license and allow, that this Serial Number can be used on multiple PCs.
This setup requires the Activation Server.
The default usage of a key is 1. It can be changed in different ways.
You can set a default value, how often a Serial Number can be used. This definition is valid for all Serial Numbers of the product. The setting is done in the TAB Activation Server, Settings.
When a key is created using the Activation Server Administration Interface, the maximum key usage can be defined. You also have to check the option: Store key in Activation Server
In case a key was already created but never used, you can add this key on the Activation Server.
Select: Add a Key on the Activation Server , add the key and define the maximum Key / ID usage
If a key was already used, you search for the key and modify it (TAB Manage Activations, Key List or Activation Requests)
If a Serial Number is used again on the same PC, it does not count as a new key usage.