Floating licensing

Floating licensing is a software licensing approach in which a limited number of licenses for a software application are shared among a larger number of users over time. When an authorized user wishes to run the application they request a license from a central license server. If a license is available the license server allows the application to run. When they finish using the application, or when the allowed license period expires, the license is reclaimed by the license server and made available to other authorized users.

The license server can manage licenses over a local area network, an intranet or virtual private network, or the Internet.

Floating licensing, also sometimes known as concurrent licensing or network licensing, is often used for high-value applications in corporate environments, such as electronic design automation or engineering tools.

There is a good explanation here:

See also

• Software metering
• License manager
• License borrowing
• License queuing