Dear learner,

For the easy understanding we'll eloborate the basics.

Joint -- it's the decision that you have to take whether to pursue PhD or not after msc completion i.e 2 years .

Dual --the student needs to do msc and then PhD simultaneously and in same college . generally it takes to complete 5 years ,as it is research related it may vary from person to person so it takes 7 years max.

All the best.