How to check the background technology in the patent publication

The background is to determine where the improvement of this patent lies. For example, in the past, cups were bare and difficult to handle. Your patent is to add a handle to the cup. Then the background technology of the patent is that the existing cup is used because it is naked, which leads to your invention-adding a handle to the cup. It is enough for the inventor to briefly introduce the background technology. Of course, to find the closest background technology, it usually needs to be determined by retrieval.