In general terms, intellectual property is any product of the human intellect that the law protects from unauthorized use by others. The ownership of intellectual property inherently creates a limited monopoly in the protected property. Intellectual property is traditionally comprised of four categories: patent, copyright, trademark, and trade secrets.
Common law did not recognize intellectual property rights. Justice Brandeis communicated this belief in his dissent to International News Service v. Associated Press:"The general rule of law is, that the noblest of human productions—knowledge, truths ascertained, conceptions, and ideas—become, after voluntary communication to others, as free as the air to common use."
Modern Intellectual Property Rights
The products of the human intellect that comprise the subject matter of intellectual property are typically characterized as non-rivalrous public goods. Essentially, this means that the same product may be used simultaneously by more than one person without diminishing the availability of that product for use by others.
The law of intellectual property can be seen as analogous to the law of tangible property in that both consist of a bundle of rights conferred upon the property owner. However, the law of intellectual property is separate and distinct from the law of tangible property. Where the right of exclusive possession is at the core of the bundle of rights protecting real and personal property, land and chattels, the same can not be said of intellectual property. The law of intellectual property is commonly understood as providing an incentive to authors and inventors to produce works for the benefit of the public by regulating the public's use of such works in order to ensure that authors and inventors are compensated for their efforts.
Congress derives its power to regulate patents and copyrights from the "intellectual property clause" of the Constitution. See U.S. Constitution, Article I, Section 8. Congress' power to regulate trademarks is constitutionally grounded in the Commerce Clause. The U.S. Patent and Trademark Office (PTO) is responsible for issuing and monitoring federally registered patents and trademarks. Although patents are exclusively governed by federal law, trademarks may also be regulated by State law. Copyrights are exclusively regulated by federal law and must be registered with the U.S. Copyright Office to be enforceable. Trade secrets are primarily regulated at the State level, and are traditionally subject to the laws of unfair competition.
Unless expressed explicitly via state statute, designs are not protected as intellectual property.