You are allowed to install any single license onto any and all compatible systems as many times as you'd like. The limitation being that you can not run the software on two machines at the same time using the same license.
For example, if you own Magic Bullet Looks, you would need to close out of whichever program you had installed it into/were using it on one system before launching it on the next one.
Running the same license between two systems at a time will result in one of them getting kicked into trial mode, or prevent the other one from launching entirely.
To have the software in use between two systems at a time, you would need to buy a second license. For more information, visit our EULA.