A machine is a physical computer where your product(s) are used.

A machine is uniquely identified with its MAC addresses, Processor ID and Hard disk ID.

You cannot add a machine manually!

When product is activated on a computer with a BLT license, it checks the Licensing Server if the machine exists.If the machine doesn't exists, BLT will check the license attributes and automatically add the machine if allowed. The only exception to this is when you receive a MachineID file due to a license configured with Pre-Authorize machine enabled.

See here how to authorize machines with BLT.

Use the home tree to explore the machines:

You can delete machines from your Licensing Server by selecting them in the tree and click the Delete button.
All the deployment licenses attached to these machines will be deleted