What is the difference between the soccer leagues in a country and in the world?

I know that FIFA is the main governing body for association football and the biggest tournie is the world cup, but what is the difference between say a country's national team-like Brazil's and then all the Brazilian leagues like Flamengo, Murici, Corinthians, etc..Is there a hierarchy? Do the smaller football clubs only play each other, and then the best players go on to represent a country on the national team to only play against other countries?|||FIFA is the governing body and it consists of 6 confederations AFC, CAF, CONCACAF, CONMEBOL, OFC and UEFA. These confederations consist of individual football associations looking after individual counties (FAs) like Brazilian Foootball Associations. Each country has its own domestic league and cup competitions run solely by the individual FA like the premier League or La Liga. The national team consists of all players that the national team coach has called up to play for the national team (a player can reject the call up). They play for their respective clubs but not necessarily in the country that they represent on the international level. For example Messi plays for Barcelona (Spain) but represents Argentina on the international level.