How does a D-MAT account work?

Question

what is a D-MAT account, why do we need it, What are the things that can be done with D-MAT account but cannot be done in another ways.

Answer 1

The only references I can find to 'D-Mat' refer to a baseball player. I did see references to 'demat' accounts. These appear to be what would be called in the US a brokerage account. They are accounts to hold shares of stock as opposed to currency.