If you are going to buy several TestLeft licenses that will work concurrently, we suggest that you buy a Floating User license for the desired number of users rather than the same number of Node-Locked licenses. Say, if you want to buy 10 copies of TestLeft, we would recommend that you purchase the Floating User license for 10 users rather than 10 Node-Locked licenses, because in this case it would be easier for you to activate the licenses and also lets you use them on virtual machines.
If you have a Floating User license, you will need to install the License Manager and activate the license on one computer only. No activation actions are needed on other computers (except for providing network access to the License Manager. See Specifying License Manager for Connection and Specifying Users Who May Connect to License Manager).
If you buy 10 Node-Locked licenses, you will have to activate each of these licenses on each computer.