Prakash,
Povident Fund (PF) is a kind of benefit for the employees. Employee will be contributing 12% of his monthly basic salary to the PF account and the employer will also contribute 12% to the same account. It is a kind of saving to you. You can avil loan from the PF account also. At end you can close the account and get the amount with interest.
Payroll is calculating of salary/ wages to the employees. As a HR you will calculate the leave availed and intimate the Loss of Pay (LOP) to the concerned person.
Regards,
Madhu