Interview question - What are the major HR activities should be done in the every organisation?

Hi Seniors, Recently i have attended interview for the post of "HR Assistant". During the interview time HR asked me about what are the HR Activities I do. I said Payroll, Recruitment, Production details, Documentation work and Legal Records Update. But Interviewer asked me only about HR activities. He asked me about Performance appraisal. I said i have studied but i didn't do it practically inside the organisation. I didn't get selected in that interview.
1) What are the major HR activities should be done in the every organisation?
2) What are the areas i have to concentrate?

Dear Seniors,
For few of my post I didn't get response from you. If Possible please guide me.
Thanks,

DearRanjeetha. MP,
Please be noted that your points like Production details, documentation work might be irrelevant while answering the Interviewer.
HR activities in core can be Attendance,leave policy,pay roll, statutory deductions,recruitment,exit,performance management,employee data base management,employee engagement,training and development,disciplinary matters,statutory liasoning etc.

It only include activities that are related to both employer and employee.

Venkata Vamsi Krishna Sir
Thank you for your guidance.