Hashish (better known as Hash) is the resin collected from the flowers of the cannabis plant. The primary active substance is THC (Tetrahydrocannabinol) although several other cannabinoids are known to occur.

Hash is usually smoked in pipes, water pipes, joints, and hookahs, sometimes mixed with cannabis flowers or tobacco. It can also be eaten.

A well-known method of using hash is the "knife-hit" method. Hash is placed on very hot pieces of metal and the resulting vapor inhaled. "Knife hits" is a method that involves heating up knives on a stove, crushing a little ball of the hash between them and inhaling the released vapor through a tube or straw. Hash cones is a method where a piece of hash is attached to a pin or metal wire and then heated.