The description must describe the invention in sufficient detail to allow a person skilled in the art to put the invention into practice without undue experimentation upon reading the patent application. Only those aspects of the invention which are described in sufficient detail may be claimed. Once a patent application has been filed it is generally not possible to add new experiments or data. Thus, it is important to be certain what it is you want to describe and claim before filing a patent application. The claims set out those aspects of the invention in which the inventor seeks a monopoly.
Claims follow the description and are numbered consecutively.
Unlike the description, the claims may generally be amended after the patent application is filed. It is common to amend claims in response to the Patent Examiner's report, in order to address issues raised by the Examiner. If you are interested in viewing patents to get a feel for their structure and layout, thousands are available on-line from various national patent offices. The United States Patent and Trade Mark Office provides access to a searchable patent database for US patents. An innovation is considered new in Canada if it has not previously been made available to the public by anyone and if a patent has not been issued in any country in respect of that invention.