Pertains to both a literary genre and more recently to an attitude or lifestyle.
The media genre generally is placed in the future and develops more on the fact that the future may not end, but may not be pretty either. Generally the storyline centres around some form of technology.
The more recent lifestyle that has evolved and coined this term is fragmented and hard to classify. It is still very new and there is debate on what the term means. Generally observation shows that "cyberpunks" are not only extremely technologically proficient, but are innately adept at it. They have a desire to know all forms of technology they come into contact with. Their attitude tends to be somewhat apathetic towards anything that doesn't directly involve them and their style of dress and personal tastes tend to be eccentrically futuristic.