How is a patent different from a copyright?

A basic view of patents and copyrights is that a patent protect inventions (the implementation of an idea), while a copyright protects the expression of an idea. For example, suppose you published an article which described a new invention. If someone tried to use your invention, a patent would prevent them from doing so. However, if someone tried to copy your actual description of the invention, a patent could not protect you but a copyright of that description could prevent them from copying it.