old emo actually was pretty much hardcore with personal lyrics lol Though some went off into a more melodic direction, but was essentially still hardcore.
emo now has turned into any music derived from punk and indie with very personal lyrics.
I don't think they're exactly genres of music, just a label people gave it to separate it from the non-personal side, even if musically, they sound the same. Also many bands labeled emo don't sound anything like each other. There are some bands that I think enforce almost all emo stereotypes, I call them emo bands( :cough: Hawthorne Heights :cough: )
Emo has pretty much grown into a pop subculture, taking over myspace and stuff lol
Goth isn't even really about music. It's a style and subculture. It's adding dark shit to your wardrobe and all this other stuff, look it up. I've never really gotten into goth, so I don't know much about it. There is goth rock, which is sorta like New Wave, sometimes punk rock kind of stuff with "dark" elements in lyrics and instrumentals. Think of bands along the lines of The Cure.
That either cleaned things up, or it made everything even more confusing
You just need to know where these things come from. Which requires actual research. You can't just ask your friends and look at a couple sites.
It really doesn't matter though, unless you just want to know why everything is everything