Final answer:
Addiction is the compulsive use of a drug despite negative consequences, while dependency is a condition that occurs when stopping drug use produces withdrawal symptoms.
Step-by-step explanation:
Addiction refers to the compulsive use of a drug despite the negative consequences it may have. It is a condition where a person becomes dependent on a drug and feels a strong need to continue using it. Dependency, on the other hand, is a condition in which stopping the use of a drug produces physical and/or psychological symptoms. This means that a person may experience withdrawal symptoms when they try to quit using the drug.