What is the main purpose of PCT patent application?

What is the main purpose of PCT patent application? The main purpose of PCT is to simplify the previously established method of applying for invention patent protection in several countries, make it more effective and economical, and benefit the users of the patent system and the patent office that has the right to manage the system. So what is the main purpose of PCT patent application? Main purpose of PCT patent application What is the main purpose of PCT patent application? (1) Establish an international system so that a patent application (international application) filed with the Patent Office (receiving office) in one language is valid in each PCT member country (designated by the applicant) where it is applied; (2) An international application may be formally examined by the Patent Office, that is, the Acceptance Bureau; (3) conducting an international search on the international application, and issuing a search report explaining the relevant existing technologies (published patent documents related to past inventions), which can be referred to when deciding whether the invention can be patented; The search report should be delivered to the applicant first, and then published; (4) The international application and its related international search report shall be published internationally and transmitted to the designated bureau. (5) Provide the Patent Office with the option of international preliminary examination of the international application to decide whether to grant the patent right, and provide the applicant with a report, which includes the viewpoint of whether the claimed invention meets the international standard of patentability. What is the main purpose of PCT patent application?