La Liga is Spanish football League. While Copa del Rey is Spanish football Cup. La Liga is the top football league in SPAIN where 20 teams in the league play each other home & away from August until May. The team that got the most points wins the league.
The Copa del Rey, or King's Cup, is the domestic cup competition in Spanish football the equivalent of the English FA Cup, or the Coppa Italia or Germany's DFB-Pokal.