Brazil’s twenty-six states and the Federal District are divided conventionally into five regions:

• Southeast
• South
• Central West
• North
• Northeast

In 2020 there were over 5,500 municipalities, which all have their own municipal governments. Many municipalities, which are comparable to United States counties, are divided into districts that do not have any political or administrative autonomy. In 2019, there were 10,607 districts and 686 sub-districts in total. 

Each of the five major regions has its own distinct ecosystem. Administrative boundaries, however, do not necessarily coincide with ecological boundaries, and, in addition to differences in physical environment, economic activity patterns and population settlement vary widely among the regions.

The principal ecological characteristics of each of the five major regions and their top socio-economic and demographic features are summarised in the following lessons.