When a patent application is received at a patent office, the relevant technical and scientific literature is searched for related publications, and then the application is examined by a professional patent examiner having the technical and legal skills to decide whether or not a patent should be granted.

A number of national patent offices and the European Patent Office possess large databases of technical, scientific and patent documents, and have access to other database resources such as genetic sequence data. The 'search' uses these resources to identify prior art relevant to the analysis of an invention’s novelty and inventiveness.

The examination procedure, details of which vary between individual countries, is termed 'patent prosecution'. The prosecution procedure may involve one or more rounds of correspondence between the patent examiner and the applicant, or applicant’s patent attorney, discussing the impact that each relevant prior art document has upon the patentability of the invention as disclosed and claimed in the patent application. In these discussions each side is expected to support its position with reasoned arguments based in established patent law.