Someone who is a "nigga" will call other niggas the word brotha because they are both black and feel a sense of connection due to that fact. They are also very likely to be "homies" or friends and thus it is a friendly gesture.
White crackers generally don't use this word, but can use the word "brother" to describe their own brothers or friends.
The way black
people say it is different from how white
people say it, as they say it
like "brotha" while white
people say it "brother".
This is due to the fact that the black community feels a sense of pride in the fact that they aren't educated. They intentionally say things in a weird and uneducated way to be a part of the group, due to black
people often living in poor conditions.
On the other hand, white
people don't really care and just say things normally. This is due to the fact that white
people don't feel like they are a part of some kind of community, because it would be weird to believe that you are part of the "white community" when almost all people in the world are white and are very different from each other.
Black "nigga" to his
homie: "How ya doin "brotha", haven't seen you in a while nigga."
Homie: "What is up my nigga! Neither have i "brotha". I thought you might be dead!
hehe."