A subscription is the concept by which You have the use and enjoyment of certain content for a specified time. You're not buying any such content.
It is the specific time that you can enjoy such content.
Before the full subscription offers on a trial period that allows you to assess the quality of the content and services offered.
During that period of time you have 2 options...:
To renew...: If you renew your subscription before it expires you will have economic benefits.
Not to renew...: The trial period is for a single use. Expired once your subscription will not have access to the economic benefits.
NOTE: Al subscribirte verás que aparece el precio completo pero te aplica el del Período de prueba
Note: When you sign up you'll see that displayed the full price but applies to you the trial period.