Given the following passage  "After the World Cup, the most important international football competitions are the continental championships, which are organised by each continental confederation and contested between national teams. These are the European Championship (UEFA), the Copa América (CONMEBOL), African Cup of Nations (CAF), the Asian Cup (AFC), the CONCACAF Gold Cup (CONCACAF) and the OFC Nations Cup (OFC). The FIFA Confederations Cup is contested by the winners of all six continental championships, the current FIFA World Cup champions and the country which is hosting the Confederations Cup. This is generally regarded as a warm-up tournament for the upcoming FIFA World Cup and does not carry the same prestige as the World Cup itself. The most prestigious competitions in club football are the respective continental championships, which are generally contested between national champions, for example the UEFA Champions League in Europe and the Copa Libertadores in South America. The winners of each continental competition contest the FIFA Club World Cup.",  answer the following question. Note that the answer is present within the text.  Question: How are countries invited to the World Cup?
continental competition