Molding or Moldmaking is the act of creating the cavity/form that carries a negative or reverse impression of an original model. Molds can be made of a rigid material, such as plaster or plastic resin, or more commonly, flexible material such as rubber. The material to use should be chosen considering the material of the model, the material to be used to make castings, and whether there are any undercuts.
Casting is the act of pouring liquid material into the cavity of a mold. After a period of time, this liquid will cure via chemical reaction or cooling. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various cold-setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster, and clay.