When employment starts, so does the employer_employee relationship. This type of relationship is defined by the kind of contract the employee has in the company. It revolves around the things they talk about and disclose to each other before the start of the employment. And before such employment, it is necessary that the company has certain basic information about the employee. This is basically for accountability purposes and for the sake of having a complete and uniform record of all employees.
Once employed, the employee usually fills out an employee form that he needs to fill out with the information requested. An employee form template would normally look like a form with the name of the company on top, and a title stating New Employee Form.