Dear Amrish,
HR professionals have penchant for coining new phrases or terms. This has been happening for the last 30-40 years. What Personnel Management (PM) of erstwhile era has become today's Human Resource Management (HRM). However, HRM of yesteryears is today's Human Potential Management (HPM) or Human Capability Management (HCM) and so on.
The latest craze is Human Resource Business Partner (HRBP). This could be yet one more phrase to stay relevant. While your question is about difference between conventional HR and HRBP, I would like to say that it is a point to ponder as to why things have come to such a pass wherein HR professionals are required to say that they are "business partners". Why Finance, Operations, Supply Chain etc professionals do not say that they are business partners?
While HR professionals may say that they are from HR, however, in all practical aspects they are still handle the issues of the PM of erstwhile times. Ask average HR Manager what is that he/she is doing something new that Personnel Manager did not do what he/she is doing differently from Personnel Managers, you will not get much different answer.
Check the prominent forums where discussion on so called issues on HR subjects happen. If you find out the statistics of the queries raised on General points Vs Points related to PM Vs Actual HR issues, you will find that actual HR queries have a minutest percentage. This minutest percentage is nothing but minutest difference between conventional HR and HRBP.
Thanks,
Dinesh Divekar