From Wikipedia,
Brazilian Portuguese (Portuguese: português brasileiro or português do Brasil; pt-BR) is a group of Portuguese dialects written and spoken by most of the almost 200 million inhabitants (2009) of Brazil and by a few million Brazilian emigrants, mainly in the United States, United Kingdom, Portugal, Canada, Japan and Paraguay.
Roughly speaking, the differences between European Portuguese and standard Brazilian Portuguese are comparable to the ones found between British and American English. As with many languages, the differences between standard Brazilian Portuguese and its informal vernacular are quite significant, though lexicon and most of the grammar rules remain the same. Nonetheless, there are still scientific debates about the status of that variant due to those differences, especially whether or not it would be a case of diglossia.