A free license allows up to 10 logged in users and an unlimited number of Guest users. However afree licence does not support publishing with custom templates and commenting.
Acommercial license allows up to 5, 10, 25, 50, 75, 100, or an unlimited number of logged in users and an unlimited number of Guest users. In addition, a commercial license supports publishing with custom templates and commenting. Note, that anonymous commenting is only available with an unlimited commercial license.
To learn more about applying and activating licences see: