What is the difference between an individual application and a company or unit applying for a patent? The ranking on the patent certificate and ...

If there is a big difference, whoever applies will have the patent right (that is, the patentee), and only the patentee can dispose of the patent, such as allowing others to use it. Patents usually belong to the applicant/company. If it is a service invention, the right to apply belongs to the company, and the inventor only has the right to sign the inventor.