How does the licensing work?

The software is licensed on a per installation basis.

Each license allows you to use the software on one machine.

If you want to run our software on 5 machines, you need 5 licenses. 

For KillDisk specifically, the license quantity also indicates the number of disks that can be erased concurrently. If you want to use the software to erase 5 disks concurrently, you would need 5 user license.