They're rather different.
Emo came fist in the late 1980's, with the rise of math rock, skramz, and related music, creating emo.
Scene evolved from emo, and decided to read further into the "depressing" emotional music. They're often associated with myspace and the 2000's.
Hipster followed with "indie" scene blowing up, and smaller grade music labels promoting their music more. (not really sure what music to put to this??)
I know nothing about ravers besides PLUR, but yeah, each group is different, but similar in their love of music.
enjoi some a trak: