Is the social security paid by yourself or after the company (on-the-job) files are managed, and the money in the social security card is paid by yourself or the company?

If you are an on-the-job employee, social security should be paid by the unit after file custody, because the unit has to bear most of the expenses.

The money in the social security card is paid by myself, and a small amount is paid by the unit. In the past, part of the pension paid by the unit was included in the employee's personal account, and now it is all included in the overall plan. So the money of your social security card now consists of two parts: your own pension and medical care+part of medical insurance paid by the company.