Apart from a) in relevance to fans from that time period, or b) the musical history perhaps found in Kerrang! magazine or Wikipedia, the term "emo" is no longer widely used to describe this.
In definition the word "emo" is mostly heard on the streets, especially in "Great" Britain to define:
a) a style of music involving Dashboard Confessional or My Chemical Romance
-- and sometimes used prejudicedly by others who term anything containing a guitar and singing together as "emo" music (despite that what music is "emo" or not has become yet more blurred with the introduction of High School Musical which is supposed to be some mainstream form of pop or hiphop music but has been latched onto by "emos" as has it by "chavs")
b) a style of fashion which can include black or neon coloured skinny jeans, Vans or Converse trainers, black eyeliner and sometimes lipstick, black dyed hair, and fitted band-logo t-shirts/cardigans etc/band-logo hoodies, or any combination of these
c) a term used cheerfully by people who are involved with one or both of the above, to describe themselves, others and it
d) a derogatory term used disapprovingly by people who do not consider themselves or their style of music/dress "emo", perhaps because they are disgusted that others categorize things they like as "emo" and they personally do not know enough about the definition of "emo" to realise that this could be wholly or partly true, so they acquire a prejudice
In truth, people should stop being so offended about the use of the term "emo" because at the end of the day it's like when black people used to be referred to as "nigger" and besides that they still find this offensive but many happily refer to themselves as "nigger".
On that basis, it should be understood that if somebody does NOT refer to themselves, their style of dress, or their band or bands they like, as "emo", they will not appreciate somebody calling them as such - as also stood in the 1990s with "grunge" and has done with "goth" and "punk".
If somebody DOES refer to themselves as "emo", they are emo and proud because they say so. It is not something like sexuality that people generally hide from; usually teenagers are happy to express what they like.
BASICALLY SOMEBODY IS NOT ACTUALLY EMO UNLESS THEY SAY SO, WHATEVER EVIDENCE OTHERS MIGHT PROVIDE THAT THEY FALL INTO THIS CATEGORY.
So note to people who have found the other above definitions of "emo" offensive - just quit worrying about it because people ARE going to call you "emo" for those above reasons, and if you call yourself "emo" then you have to prepare for people to carry on like that. It means they are small-minded and don't know what it connotates to.
I know that sucks, but it's the sad truth. The gift of free speech in places such as Urban Dictionary is a brilliant thing; the fact that people use the anonymy of the internet to say abusive things from a safe distance holed up in their boring homes, when it proves they have nothing to do, is an unhappy truth in itself, but being offended by any of that just means that they have got what they hoped for - and proves their point about emo stereotypes.
If someone bullies "emos" about being "emo" then that shows what an idiot the person is. If the "emo" cries about it and gets all messed-up then the bully wins.
Hope that helps a lil. :)
(example of opinion)
"Kerrang! magazine is only read by emos"
(example of small-mindedness)
"That kid is an emo"
(example of stereotype)
"That kid SAYS he is an emo"
(example of justification, which is needed before somebody makes a comment like "That kid is an emo")
1. Girls say they like "sensitive guys" (lie)
2. Guy finds out, so he listens to faggy emo music and dresses like a dork so chicks will see that he is sensitive and not afraid to express himself (lie). He dyes his hair black, wraps himself in a stupid looking scarf, develops an eating disorder, and rants about how "nobody understands".
3. Now an emo guy, he meets Emo chick and they start dating, talking about how their well-off suburban lifestyles are terrible and depressing (lie)
4. Emo guy is just too much of a pussy. His penis is too small, he's too depressed to bathe, and has more mood swings than emo chick, and he doesn't even have a menstrual cycle. Emo chick dumps him, saying "It's not you, it's me." (lie) as she drives off with Wayne, the school jock and captain of the football team.
5. Emo guy goes home and cries, proceeds to write a weak song and strum a single string on his acoustic guitar. Another emo chick sees how he is so in touch with his feelings, and the cycle continues.
This is the sad truth of the emo lifestyle/music, and now that I look at how pathetic it really is, maybe the emos DO have something to cry about!
boyfriend: I'm too sad to have sex.
girlfriend: I'm sad too; lets have sex and cry.
boyfriend: I'm already crying.
XxSlavetoAnguishxX: omg my gf just left me
acidburnedsoul: that sux man
XxSlavetoAnguishxX: i blame myself only i'm such an ass *cries*
acidburnedsoul: dude come over to my house and we can cut ourselves together
XxSlavetoAnguishxX: okay *cries*
acidburnedsoul: omg dashboard confessional has a new cd, i preordered it already
XxSlavetoAnguishxX: dude they're my favorite band to self-mutilate to
acidburnedsoul: i prefer to cut myself while watching Napoleon Dynamite on my bigscreen
XxSlavetoAnguishxX: dude that movie is so deep. i cry every time i see it
acidburnedsoul: me too. i hate myself
XxSlavetoAnguishxX: yeah we're such tortured souls, nobody understands how hard life is for us
acidburnedsoul: yeah we got it tough dude. pass the tissues
I just thought I'd clear that up after all of these "definitions" in which I have encountered an unbelievable amount of people who try to pass off their blatantly false pretenses as fact, and are slowly infecting others with their high-horse, holier-than-thou bullshit. Because honestly, with your ridiculous definitions, Beethoven, George Gershwin, and Britney Spears are/was "emo bands."
Now, onto the real definition.
In the early 90s there was a movement in the hardcore genre that came to be known as "Emotive Hardcore," spearheaded by Rites Of Spring. Harder-core-than-thou kids, who swore by Dischord Records a la Minor Threat, actually coined the term "Emo" as something of a put-down for the kids who really liked Rites Of Spring, Indian Summer and this new wave of "Emotive" Hardcore bands. That's right, "Emo" was once not something kids called themselves. The field exploded outwards from there - Level-Plane Records has always been the most famous Emo label. Acts like Yaphet Kotto, I Hate Myself, Saetia, Hot Cross, A Day In Black And White, Funeral Diner, I Would Set Myself On Fire For You, You And I, and hosts of others came in the next decade. Most emo bands have since broken up, but there's still the occasional hold-out (again, the majority of Level-Plane Records' roster has been a procession of emo acts). Like most DIY hardcore/punk of the time, a majority found its way onto vinyl and not much else. Some people consider bands like Fugazi, and later Sunny Day Real Estate, a progression of emo, but personally, I don't quite follow that philosophy.
Often, more recently, this gets intertwined with post-hardcore, and understandably so - that's nothing to make an issue of, since well shit, at least it's close.
Since the late 90s, though, bands have been emerging in the vein of Taking Back Sunday, Dashboard Confessional, and the thousands of their clones. As far as I can tell, some lazy journalist somewhere, writing an article about them, decided "Well, fuck, no one knows what emo is anyways, so I'll call these bands "emo" - sounds more appealing than bubblegum pop rock..." and the spiral continued downwards into the current amalgomation of bands MTV has told everyone is "emo."
Somehow, people decided that "emo" meant "emotional," which is obviously bullshit, as 99% of bands make music to illicit emotion, which would make "emotional" a completely all-encompassing genre from classical to opera to pop to rap.
Hope that helps.
Rites of Spring is emo.