The World Cup, the European Cup and the Copa America (South America) are held every four years. The AFC Asian Cup, the African Cup of nations, the CONCACAF Gold Cup (North America) and the OFC Nations Cup (Oceania) are held every two years. The FIFA Confederations Cup is held every four years, one year before the World Cup. It consists of all the winners from above tournaments and the hosts of the World Cup. International friendlies are usually played before every big national tournament, or every summer and winter break if I'm not mistaken. The World Cup qualifiers start two years before every World Cup. In Europe, there are 8 groups of six teams, and one groups of 5 teams. Every national team that finishes first in it's group is automatically qualified for the World Cup. All the teams that finish second in the group compete in a sort of mini play-off tournament, and the winners also go to the World Cup. It's basically the same in the rest of the continents, but with less groups and games are usually played during summer. The groups are determined by a draw (Lottery? I don't really know what word to use). The biggest rivalries in International football are Brazil vs Argentina, Netherlands vs Germany, England vs Germany and maybe some more. International football rivalries aren't that big. Big club rivalries are: Barcelona vs Real Madrid, Liverpool vs Manchester United, AC Milan vs Internazional Milano, Roma vs Lazio, Rangers vs Celtic, Manchester United vs Manchester City, Liverpool vs Everton, Arsenal vs Tottenham, Real Madrid vs Atletico Madrid and there are much more, but the first three/four/five are the biggest imo. The Club World Cup consists I think of clubs who won their own continental club tournaments like the UEFA Champions League (Europe) or the Copa Libertadores (South America). The winners of these tournaments compete against each other in the Club World Cup. It's not a very important tournament. Biggest club tournament imo is the UEFA Champions League. Anyway, that's all. Hope I helped.