The degree certificate and the supplementary degree certificate from Pune University are two different documents that serve different purposes. Here's a brief overview of the difference between the two:
In summary, the main difference between the degree certificate and the supplementary degree certificate from Pune University is that the former is the main certificate issued to a student upon successful completion of their course, while the latter is an additional certificate issued to acknowledge the student's success in clearing failed subjects in the supplementary examination.
A supplementary degree certificate, also known as a provisional degree certificate, is granted immediately after you pass and clear the final year of the degree. It includes your final year grade sheet as well as your transfer certificate (college leaving certificate).
It is an emergency provision made by the university for students who are applying for jobs or who have already been hired and want to submit their credentials.
After passing and being cleared from the degree, you will be given the primary degree certificate. It is actually given after a period of roughly 6–8 months from the final year result. It is your choice to apply for it or not. Those who wish to apply, however, must first log into the university's convocation site and create an account. Pay the requisite application fee and collect the certificate at the convocation event.
The fundamental difference between a supplementary/provisional degree certificate and a main degree certificate is that the main certificate is awarded after you have received your supplementary/provisional degree certificate.