What is the patent claim to be written when applying for a patent, and what is its function?

The claim is the most basic part reflecting the scope of patent protection. The content and degree of patent protection depends on the patent claim.

Whether the analysis is infringing and whether the analysis is patentable depends on the content of the claim.

It can also be said that the claim is the core of the patent.

Claims are very important, some inventions are good, but patents are invalid because of poor writing of claims.