The term "illicit drugs" refers to a broad range of substances that are prohibited by law due to their potential for abuse and harm. These drugs include, but are not limited to, narcotics such as heroin, cocaine, and morphine; stimulants like amphetamines and caffeine; depressants like barbiturates and benzodiazepines; hallucinogens like LSD and mescaline; and cannabis. The use of these substances is generally considered to be unlawful, and their possession or distribution may result in criminal penalties. Illicit drugs are often associated with negative consequences such as addiction, health problems, and social disruption, making them a significant public health issue.