The people living in the favelas are the poor, and the rich people live in the city. And the vast majority of the population is black.
Most of the buildings in favelas are made out of cheap materials, like wood, plastic, glass and scrap material.
The people usually build their houses themselves and invite their friends to help them build.
The favelas are illegal, because the people do not pay tax. Despite the attempts to cleanse Rio de Janeiro and São Paulo of favelas, the poor population grew at a rapid pace.
In 1969, there were approximately 300 favelas in Rio de Janeiro; today there are twice as many. In 1950, only 7 percent of Rio de Janeiro's population lived in favelas, nowadays this number has grown to 19 percent or about one in five people living in a favela.
Census data shows that in 2010, about 6 percent of the population lived in slums in Brazil.
Crime (and especially the cocaine trade) is common in favelas, as many of the people have no other way to make money. The cocaine trade has affected the favelas. The favelas tend to be ruled by drug lords. Police in Rio de Janeiro are seeking to take back control of many of the cities main favelas from drug gangs before playing host to matches in the 2014 World Cup and the 2016 Olympic Games.
The photo above shows a resident who was shot and lies on the ground as others help him during a police operation at a slum in Rio de Janeiro
Regular shoot-outs between traffickers and police and other criminals, lead to murder rates in excess of 40 per 100,000 inhabitants in the city of Rio and much higher rates in some Rio favelas.
The favela Rocinha (69,300 - number of inhabitants in 2010, 150,000 – estimated approximate true number of inhabitants of Rocinha) is the largest favela in Rio de Janeiro and in Brazil, and is located in Rio de Janeiro's southern part. Rocinha is built on a steep hillside overlooking Rio de Janeiro, and is located about one kilometre from a nearby beach.