Real Madrid plays in white and is based in Spain's capital, Madrid. FC Barcelona plays in deep red and dark blue stripes and is based in Barcelona, in the region of Catalonia. The two cities are about 500 km apart, which is roughly the distance from London to Paris. When the two clubs play each other, the match is so big that schools, restaurants and even other sports often stop to watch.
Spain has been the home of some of the greatest footballers ever. The Spanish national team won the World Cup in 2010 and the European Championship twice. Spanish coaches and Spanish ways of training are taught in football schools around the world. The style is called 'tiki-taka' - quick, short passes between players, almost too fast to follow.
Football lessons start very young in Spain. Even small village schools have a 'fútbol' practice on the playground every break. Children pick teams, set jumpers down as goalposts, and play until the next bell. Some big clubs run academies for children as young as seven, where they live, study and train all in one place.
Spanish stadiums are huge. The Camp Nou in Barcelona can hold around 99,000 people. The Santiago Bernabéu in Madrid holds around 78,000. When the crowd sings, the sound has been measured at over 100 decibels - as loud as a chainsaw.