appearance patent mainly refers to beautiful appearance, for example, the design patent of iPhone.
utility model mainly refers to minor structural improvement, and its basic requirement is substantive features and progress. For example, progress has been achieved by adding an electronic component or improving its structure.
The hardware of the invention patent is basically the same as that of the utility model, but the basic requirements have been improved, and the requirements are outstanding substantive features and remarkable progress. The most important thing is that it can involve the content of software, which is called method invention, such as software algorithm, implementation steps and so on. In addition, there are integrated circuit layout design and so on.
Obtaining intellectual property rights is a delicate job. It is recommended to contact a professional patent agency, who will help you with everything.