What's the difference between "made from" and "made of" [duplicate]

As a general rule, if an object consists of a material that has not been changed in any significant way then we say "made of":

This table is made of wood.

That table is made of glass.

If, on the other hand, the material is significantly changed in the process of making the object, then we generally say "made from":

Paper is made from wood.

Glass is made from melted sand.

You can also use "made out of", especially when referring to a surprising use of the original material:

I have a Christmas tree made out of wire coat hangers.

Note, however, you will encounter many examples in actual usage that contravene the above principles.