A license file is a file that represents a set of license rights. Many software applications require users to obtain a license file to gain access. Its purpose is to prove that a user, by holding a valid license, is authorized to access a software application. The license file typically must be available locally so that the application can check it at launch.
Also known as a LIC file, it can also contain registration information that allows certain features (like paid features) to be used. License files are a method for software vendors to control access to their products by, for instance, allowing access only for paying customers.
If you’re a software developer looking to move away from using license files to control access to your product, and to replace it with a modern solution, you can find more information on the 10Duke Licensing Engine here.