Illegal drugs are substances that are prohibited by law and are not meant for human consumption. They include a wide variety of psychoactive substances such as narcotics, stimulants, hallucinogens, and depressants. There are several different terms that can be used as synonyms for illegal drugs, such as controlled substances, illicit drugs, banned substances, restricted drugs, and unlawful substances. These terms are often used interchangeably to refer to substances that are considered dangerous, addictive, and harmful to individuals and society as a whole. The use of these drugs has serious consequences, including legal sanctions, physical and mental health problems, and social and economic costs.