R "form verification login
T" form approval
D "form conformity statement
authentication refers to the conformity assessment activity that the certification body proves that the products, services and management systems meet the mandatory requirements or standards of relevant technical specifications.
certification here includes system certification and product certification. System certification can be done by ordinary enterprises, and it is also a certification that makes customers feel at ease about their own enterprises or companies, such as ISO91 quality system certification. Generally, the price is determined by the number of enterprises or companies.
product certification is relatively extensive, and the prices of products with different specifications and different product certifications are different. Of course, their uses are also different, such as CCC national compulsory certification and CE EU safety certification.
in addition, the price of the same kind of products is different if they are certified by different products. For example, if air conditioners are exported, they must be certified by relevant foreign products.