Nigga

A friend or a homie, different to Nigger which means a slave in the olden days used to describe black people.

White Person: Whats up Nigga
Meaning whats up homie

White Person: Whats up Nigger

Meaning they are describing the person as said.

Pronunciation:
Nigga- N-I-G-G-A
Nigger- Nig-ger