A license manager is required to administer the ArcGIS Concurrent Use installations of ArcGIS Desktop, ArcGIS Engine, and their extensions. The license manager allows you to install and use Concurrent Use versions of these products on as many machines as you want. The number of Concurrent Use licenses in your license file determines the number of users who can simultaneously run the software product.
To use ArcGIS 10.8.1 Concurrent Use software, install and use the latest License Manager.
ArcGIS licenses can be served from any platform of License Manager to any platform client software. For more information on administering the license manager, see the License Manager Reference Guide, lmrefguide.htm. After installing the license manager, this guide is also available from Start > Programs > ArcGIS > License Manager > License Manager Reference Guide or in the installation folder at C:\Program Files\ArcGIS\LicenseManager\Documentation\lmrefguide.htm.
See Installing the license manager for installation information.