Intellectual property is a form of new knowledge or a creation which is protected by various kind of intellectual property right (IPR). IPRs are rights awarded to inventors or creators which allow them to prevent others from making unauthorized use of their property. They include patents and copyright, which offer protection for limited periods. In the context of public health, patents are the most important IPR. Patents provide the inventor with the right to prevent others from making, selling, distributing, importing or using their invention, generally for a period of 20 years. To obtain a patent the inventor must also disclose the knowledge on which the invention is based. The temporary exclusion of direct competition provides an incentive for invention and innovation by allowing producers of a new medicine to set prices at a level necessary to recoup the costs of their research and development expenditure and make a return on their investment.