Made from the paste of the sap of the cannabis plant, hash or hashish contains a higher amount of psychoactive chemicals compared to weed. Just like recreational weed, hash induces euphoria to its users. Medically, it is used to treat depression, anxiety, nausea, and pain.
Because of its higher THC concentration, less hash is needed to get the same high as its plant form. There are variations in quality because of the plant where it came from and its online weed shop distributor, but users generally moderate the amount they consume to avoid any negative effects.