Human resource management is a vast subject.
The role of Hr vertical in an organisation is all about management of manpower required against demand and supply of a company.
In broader sense,
The role envisages all the activities starting from recruitment of weight talent, its induction training, welfare, compensation ,documentation administration, discipline till exit formalities and fulfillment of regular statutory compliance as required by the company against employees and organisation as a whole as per the prevailing laws applicable as on date.
Whats your company business,how it operates, what all compliance it requires all such things need to be known by HR, and must formulate a policy, guidelines and manuals etc. Hope this gives you some idea apart from unique terminologies like performance management procedures, KPIs and KrAs etc
And many more which will require an excellent competency in human resource management and still it's not the end...