Hi,
According to my knowledge, HR is a bridge between the employer and the employee, and they have to serve them both equally. Hardcore HR functions include:
1. Recruitment - To select the right candidate for the right position.
2. Payroll - To manage the salary, compensations, and calculations with accuracy and zero percent mistakes.
3. Administration - Overall maintenance of office property.
4. Employee retention - Grievance handling, appraisals, promotions, taking timely feedback, and lastly, solving their queries if any.
5. Maintain good relations with employees (colleagues) because for an HR, their employees are their biggest assets as these employees keep the company moving.
I believe there are still more points to consider.