The employer needs to know the complete address of the employee for a number of reasons. One is for payroll purposes. Setting up an account for a person requires him to provide his address. Another reason is that if something wrong happens, they would know where to locate him or his family. The company also needs an employee's address so that they can be certain of his identity. And another reason would be for mailing of anything necessary purposes.
Other possible parts of the employee form template are the date of hire of hire of the employee, whether he is on a part time schedule or a full time one, a section where he has to say whether he just graduated or not, his pay rate, etc.