Hard and soft drugs are loose categories of psychoactive drugs. This distinction is used in both official and casual discourse. The term hard drug generally refers to drugs illegal for nonmedical use that lead to profound and severe addiction, as opposed to soft drugs that are either only mildly psychologically addictive or non-addictive.
A large part of the distinction is a subjective, socially conceived notion of the consequences of usage for each drug. Depending on context, a particular drug can be categorized in many different ways for many different reasons. Even though there is a distinct difference between hard drugs and soft, many nations around the world continue to discourage soft drug use and refuse to recognize the clear distinction between the two. Surprisingly, some hard drugs are legal in most parts of the world (such as alcohol and nicotine) and soft drugs are illegal (such as cannabis and LSD).

in between "hard drugs" and "soft drugs"
Examples of soft drugs include cannabis, mescaline, psilocybin, and LSD. MDMA and caffeine are sometimes included as soft drugs, see above. The term soft drug is most usually applied to cannabis (marijuana or hashish) because it is not associated with deaths,[1] crime or violence amongst users,[2] and is without evidence of physical addiction. [3] Cannabis has been studied at the University of California, Los Angeles, and it was shown that a lung cancer link isn't evident in the studies.[4] This distinction between soft drugs and hard drugs is important in the drug policy of the Netherlands, where cannabis production, retailing and use come under official tolerance, subject to certain conditions. Other drugs such as psilocybin mushrooms and LSD are also considered soft drugs by many because there is no evidence of physical addiction and it is nearly impossible to overdose on these drugs.