To use Ontolica, you must purchase a license that matches your SharePoint installation and other requirements. For example, each license provides support for a specific number of servers, technical support options, updates, feature options, etc. Some licenses, such as trial licenses, may also have an expiration date.
When you purchase a license, you will receive a license file, which encodes a serial number, your selected options, and other information. If your installation changes (e.g., because you add more servers to your farm), then you may need to contact SurfRay and update your license. Once you have done this, you will receive a new license file.