US means that the patent has entered a specific country-the United States, and it will be examined by the US Patent and Trademark Office. After authorization, there will be a US patent certificate.
CN indicates that the patent has entered a specific country-China, and will be examined by China National Intellectual Property Administration, China. There will be a China patent certificate after authorization. (Of course, you don't have to bother to apply for a patent in China. You can submit it directly to China National Intellectual Property Administration. )
When you enter a specific country, you need to give priority, that is to say, the contents of patents in the United States and China are the same as those in WO (which may be revised during the examination of the Patent Office), and the time of patent publication is the time of WO.
For example, if you buy a house, you know the seller through an intermediary. You need to pay the intermediary service fee and then spend a sum of money to buy a house from the seller. The intermediary is the international bureau, the seller is a specific country (the United States), and the real estate license is an authorized patent certificate.
Of course, you can also go beyond the intermediary, buy a house directly from the seller, and submit a patent application directly to China National Intellectual Property Administration as mentioned above.