Hello,


There is not huge difference between them:
Post Graduate Diploma in Management (PGDM) and Masters in Business Administration (MBA) are both management courses at Masters level.
After doing PGDM course, you are offered a Diploma certificate. While , after completing an MBA programmes, you receive a degree.
MBA courses focus more on theoretical and technical aspects of management rather than a practical approach. PGDM courses have an industrial orientation and focus on skills based on market environment and business environment.

I hope this helps.