Simply put, the inventor is the person who made the invention; The applicant is the person applying for a patent, and the applicant and the inventor may or may not be the same person. For example, if you apply for a patent for an invention made to complete the company's task, the company should be a legal person applicant, if the patent licensing company is the patentee. Patent authorization must be granted to the applicant.
Applicant: It is the patentee, a natural person or a company. If more applicants are added, the application fee will increase. The inventor can only be a natural person, and no one will increase the cost.