In conventional casting process, what we prepare for the purpose of filling the molten metal is nothing but mould . In some cases for the purpose of mass production.

In conventional casting process there will be two basic parts called cope and drag. First we will place the part to be cast up side down and upon that place the down part drag. Now fill the part with the moulding sand. Now turn it and place the remaining part upon it and fill the cope part. Now by removing the cope part and remove the part inside the drag part. Now we will get a cavity. That is called mould .

In mass production process, in order to avoid all the process of making the mould we will make those upper and lower parts with some metal. That is called  as die.