That last sentence was carefully worded.
As the words suggest, these are the sections of the patent application where you describe and specify what your machine or process is and claim how it differs from previous patents and technology.
The drawing to the left is an actual drawing from a patent and is described in the patent in the following way
- Fig. 1 is a semi-diagrammatic view of a tent and tent frame according to one embodiment of the invention, showing the tent as erected;
Yes, I know it sounds complicated, but we do have some good tips on writing descriptions for a patent application.