The U.S. Patent system is founded on an elegantly simple process for encouraging innovation. You come up with a unique idea that is not obvious to someone who is familiar with the subject area. You describe it in sufficient detail that others can duplicate it. In return for doing so in writing, the government will protect your exclusive use of the idea for 20 years. As an example consider Apple, known as one of the more innovative companies in recent history. Making an electronic device in the shape of a rectangle is laughingly obvious, but who would have thought to round off the corners?

Apple Patent