Z:gnu-www-ja-shouldbefree--6e156e-This reflects a crucial differ/en

This reflects a crucial difference between copies of programs and cars, chairs, or sandwiches. There is no copying machine for material objects outside of science fiction. But programs are easy to copy; anyone can produce as many copies as are wanted, with very little effort. This isn't true for material objects because matter is conserved: each new copy has to be built from raw materials in the same way that the first copy was built.