The heart of a patent application is comprised of the description and the claims.
 
The description includes specifications and drawings, and discloses how an invention is made and how it is used. The claims are based upon the description and set out the legal limits of what is protected by the patent.
 
Although it is thought that the claims are the most important part of the patent, when an inventor reviews a draft patent application, the description, not the claim, should be the focal point of the review because of the following:
 
The description cannot be amended to include new material after an application is filed. The claims can be amended after filing but only to the extent that they claim what is described in the specification or shown in the drawings.
 
The description is also the most important part of the patent when trying to determine if your invention is patentable in view of an existing patent, that is, when your application is being studied for its prior art disclosure, if an invention is described in a printed publication, such as a patent (which is considered a printed publication), more than one year before your patent application is filed for the invention, the invention will not be patentable. Therefore, in reviewing a patent for its prior art effect, the specification and drawings should be the primary focus, not the claims.
 
The claims are analyzed by an examiner to determine the scope of protection of a patent. This is important when deciding if your product infringes that of a competitor or if the competitor’s product infringes your patent. The claims are also useful in determining how to “design around “ a patent so that you do not infringe an existing patent.