I know almost nothing about engineering, so my question is very basic. Basically, assuming that I have a scheme for a prototype of something, how do make it from a raw material? If it is still not clear what do I ask, let me further simplify. Suppose that I want to make a well-shaped iron ball - how do I make it? How to shape the melted iron into a ball? Or into a nail? Or into a screw? Or into some other wanted shape? I guess this type of problems has its own name, but I don't know what that name is? It would help me for further googling about such problems. It would also help if you know youtube videos or something like that where the process of shaping can be better visualized.