A good search is hence usually quite important to the success of an application for patent and is always informative no matter the result. Even in the cases wherein the innovation is found to have been previously disclosed it may be quite useful to learn in what manner this was done. If there was little success with it on the market then perhaps the innovation was flawed and the remedy to the flaw provide the basis for a patentable worth having. In many cases there may be a number of references in the prior art which are similar to the innovation searched and which collectively render the particular innovation searched unpatentable but which also together exhibit lack some aspect which can now be recognized though it wasn't before, and a basis for a patent thus developed. There is also an Abstract required which is what is provided in the Patent Office's computer data base that goes back to 1970.
Every section has a purpose.
The Background sets the stage, shows the examiner you've done your homework and points out what is considered to be lacking in the prior art. It also provides a definition of what is considered to be the proper scope of the prior art. This can be decisive in prosecution. The Summary defines the intent of the invention and how it is achieved in language which is less constrained than that required of the claims. The drawings are described briefly as a courtesy.