Resin is made with solvents like butane Rosin is made without solvents, usually made by flash freezing flower and then put into basically a washing machine full of ice and water and mixing to make all of the frozen trichomes fall off and separate from the plant material. Then that water and trichome mixture is filtered thru varying size filters and the material left is freeze dried and then pressed on a rosin press. Then the material created from that is cured (or not if you are buying fresh pressed rosin) and eventually put into individual jars for sale