The description (PDF 0.04 MB) immediately follows the title. It is a detailed explanation of the invention. It should include all relevant information. It must be sufficiently clear and complete to be understood by others; such as to allow a person reasonably skilled in the same art to be able to fully replicate the invention without needing further details.
The description should set out the background of the invention and also explain any particular problem that the invention solves, and what it does.
Please note in particular that additional information cannot be added or the description broadened after you have filed the application.
A filing date cannot be secured in the absence of a description of the invention which is the subject of the request for grant of a patent.