The Complete Season Ticket gives members the right to attend, always in the same seat (except in cases of force majeure or when official competition rules dictate otherwise), matches played at the Camp Nou in these official competitions: La Liga, Champions League, Europa League and Copa del Rey. It is automatically renewed at the end of each season.
The League Season Ticket grants the right to attend, always in the same seat, matches in the Liga de Fútbol Profesional and the Copa del Rey. The club offers the possibility for members with a Complete Season Ticket to switch to a League Season Ticket, thus saving 25% of the total cost of the Complete Season Ticket. At the end of each season when the ticket is renewed, the season ticket will always return to the status of being a Complete Season Ticket. The money will be paid into the applicant member’s bank account once the change of ticket type has been formalised at the Barcelona Supporter Services Office.
The Definitive League Season Ticket, unlike the League Season Ticket, and as its name suggest, is definitive forever.
If you would like further information on the change of season ticket type (Complete to League), please see the question How can I change the type of season (Complete -> League)?.