Enterprise patent application process?

What is the patent application process of enterprises? What's the difference between patent application and individual patent application? How to find out whether something has been patented? To apply for a patent for invention or utility model, a written request, a specification, an abstract thereof, a patent claim and other documents shall be submitted. The date when the Patent Office receives the patent application documents shall be the filing date. If the application documents are mailed, the postmark date shall be the application date: ① If the applicant files an application for a patent for invention or utility model in China within/0/2 months from the date when the foreign country first filed an application for a patent for design or within 6 months from the date when the foreign country first filed an application for a patent for design, he may enjoy the priority according to the agreement signed between the foreign country and China or the international treaties to which both countries are parties, or according to the principle of mutual recognition of priority. An applicant who files an application for a patent for invention or utility model with the Patent Office on the same subject within 12 months from the date when he first filed an application in China may enjoy priority. (2) Where the applicant claims priority, he shall make a written statement at the time of application and submit a copy of the first patent application document within three months; Failing to submit a written statement or a copy of the patent application documents within the time limit shall be deemed as not claiming priority. An application for a patent for an invention or utility model shall be limited to one invention or utility model. Two or more inventions or utility models belonging to a general inventive concept may be filed as one application. An application for a patent for a design shall be limited to a design used by a product. Two or more designs of products sold or used in the same category in sets may be filed as one application. Within three years from the date of filing, the Patent Office may, at the request of the applicant at any time, conduct a substantive examination of the application; If the applicant fails to request substantive examination within the time limit without justifiable reasons, the application shall be deemed to have been withdrawn. When the Patent Office deems it necessary, it may examine the application for a patent for invention on its own. When requesting substantive examination, the applicant for a patent for invention shall submit reference materials related to his invention before the filing date. Where an application for a patent for invention has been filed in a foreign country, when the applicant requests substantive examination, he shall submit the information retrieved from the examination of his application in that country or the information on the examination results. If it is not submitted without justifiable reasons, its application shall be deemed to have been withdrawn.