Ask HR: What, really, is the work of a HR manager in a modern workplace?

I am a HR manager in a local company. Recently I was part of a panel discussion where someone mockingly asked me what HR really does. While I have studied HR and practised it for some time, I did not feel confident with my answer. How should I handle this question next time? 

There are many different versions of not only what HR is but also its purpose in organisations. These versions vary based on context, primarily shaped by leadership, stage of growth of an organisation, organisational aspirations, as well as differences in the perspectives among those making attempts to plumb the import of HR. Some consider HR to strictly be about people strategy while others see it merely as a garage for grievances and odd issues that arise in organisations. While it may mean different things to different people and organisations, HR is nevertheless not a nebulous trade.
 
HR should, like all other functions, contribute to the overall objectives of an organisation. The common mistaken notion that HR exists merely to secure employee welfare ought to be disabused. An organisation that meets its overall objectives is well placed to take care of its people. Granted the differences in definition, a broad dual purpose of HR is to contribute to organisational success by facilitating optimal people output as well as helping to nurture an environment in which employees could enjoy meaningful career experiences. This calls for a view that an organisation and its people are not two opposed or competing parties, but partners. People issues are business issues.