Commercial license
A commercial license allows fonts to be used for commercial purposes. The cost of this license depends on the total number of employees of the licensee* (and not only on the number of people using fonts).
*If you license fonts for your own use, you (or your company) are the licensee. If you are a designer (or a design studio), then this is your client.
Trial license
The trial license allows you to use fonts for personal purposes for free. Trial fonts contain all available styles and the full character set, but cannot be used publicly or for commercial purposes.