Indie, short for independant, applies to independant media, usually film or documentary and is also, more commonly, applied to a sub-culture (not a label) which involves generally music, behaviour (and in a few cases, style of dress). These people are also referd to as Indie Kids or Indie Rockers, of which most dislike these terms as it labels them in a certian group, which the the opposite object of independant! Most dislike the mainstream and the 'in-trend' and wear, listen to and do what they feel like without following fasions and rules (and im not talking about the law, Indies are just as likely to break the law as anyone else) and will always be themselvs and not put on an act for popularities sake. Obviously Indie is also a type of music which is generally soft-style rock without screaming or moshing sometime mixed with synthisised music and electronic, and is also generally on a independant record label and not well known. Altough indie is not a label it does have all sorts of connections to other groups and indie is commonly assocatied as a type of rocker, Indies, along with most other rockers, are at a long lasting 'social war' with chavs and scallies and contrary to popular belief are not in a long lasting rivalary towards Emo or sometimes Metalheads. There are also Indie wanabees and posers which are not themselvs and just act it!
Just remember people... Indie is not a label, group or class!