Drug detection refers to the process of identifying the presence of illegal substances or controlled medications in a person's system. This can be done through various methods, including urine, blood, saliva, or hair tests. Each method has its own advantages and limitations, depending on factors like the type of drug, the time since use, and the individual's metabolism. In many settings, such as workplaces or schools, drug detection is used to ensure safety and compliance with regulations. Law enforcement agencies also utilize drug detection techniques during traffic stops or investigations to identify impaired drivers or individuals involved in drug-related crimes.