HRM is overall concept of human resouuces like recruitment, selection, induction, trianing, compensation, performance appraisal, employee development, employee seperation.
Where as HRD is limited to employee training , employee development, succession planaing, talent management etc.
For the companies HRM is main objective that is why we are named as HR / Personnel Department.
For State/Central Governments, HRD is main objective, that is why have Ministry of HRD.
I hope u understood.
Cheers
PB Ram Swaroop