HRM means Human Resources Management. This means that a person who is the head of this department will be in charge of checking all aspects of the human workforce. The HR heads will make sure that they will only get the best of the best for the companies that they work for. HRD means Human Resources Development.
The head of this department will be in charge of developing the skills of the employees so that they can contribute more to the company or they can fit better with what the company would like to achieve. The HRD will organize talks and seminars that can help improve what people need to work on.