Explanation

Opioids are the drugs, which bind to opioid receptors in the central nervous system and gastrointestinal tract. Drugs derived from the extract of Opium poppy, $e.g.,$ morphine, heroin, brown sugar, etc. Heroin, commonly called smack is chemically diacetylmorphine, which is a white, odourless, bitter, crystalline compound. This is obtained by acetylation of morphine, which is extracted from the latex of poppy plant Papaver somniferum