Drug cultures are examples of countercultures that are primarily defined by spiritual, medical, and recreational drug use. They may be focused on a single drug, or endorse polydrug use. They sometimes eagerly or reluctantly initiate newcomers, but their main functions are to share drug experiences, to reduce harm by providing knowledge of how to use drugs as safely as possible, and to exchange information on suppliers and avoidance of law enforcement.
Drug subcultures are groups of people united by a common understanding of the meaning, value, and risks of the incorporation into one's life of the drug(s) in question. Such unity can take many forms, from friends who take the drug together, possibly obeying certain rules of etiquette, groups banding together to help each other obtain drugs and avoid arrest, to full-scale political movements for the reform of drug laws. The sum of these parts can be considered an individual drug's "culture".