This has been adapted from responses I gave on Yahoo! Answers.
What they protect:
- Copyright protects original 'literary, dramatic, musical and artistic works'.
- Patents protect inventions (methods/processes or products/composition of matter, or machines).
Requirements for protection:
- Your work can be copyrighted as long as it is original.
- In order for an invention to be patented, the inventor must prove that the invention is novel, inventive and useful. Jurisprudence (i.e. previous court decisions) define these requirements. The patent office determines whether an application meets these criteria.
How you get protection:
- Copyright protection is automatic upon creation, although registration may be recommended to prove originality to either defend against or pursue an infringement claim. For registration offices around the world, click here.
- Patents require registration through a patent application, which goes through a costly, lengthy and laborious patent examination, during which the patent application is published.
Duration of copyright protection:
- Copyright protection is for the lifetime of the author and an additional 50 or 70 years (depending on the country) after the author's death. Also see here.
- Patent duration is shorter than copyrights (around 20 years, depending on the country and other factors).
What acts constitute infringement:
- Copyright prevents others from reproducing, adapting, distributing, publicly displaying or performing a copyrighted work without permission or license from the copyright owner.
- Patents prevent others from using, manufacturing, selling or importing the method or product without a license from the patent owner.
Where your work is protected:
- Copyrights are protected in most countries of the world. For a listing of countries that are party to the Berne Convention, see here.
- Patents are jurisdictional; your invention is protected only in the countries where you have a patent in effect. It is costly to patent in many countries. While the Patent Cooperation Treaty and the European Patent Office somewhat simplify protection your invention in multiple countries, the cost and time involved are still considerable.
US Copyright Office FAQs
US Patent and Trademark Office