It can be used for both male and female friends, and it's a very versatile word.
Here are some other ways to say "friend" in Brazilian Portuguese:
* "amiga" (ah-mee-gah) - female friend
* "companheiro" (kom-pahn-yay-ro) - male companion
* "companheira" (kom-pahn-yay-ra) - female companion
* "colega" (koh-leh-gah) - colleague
* "camarada" (ka-ma-ra-da) - comrade (often used for political friends)
The best way to choose the right word depends on the context and the relationship you have with the person.