A recurring deposit (RD) is a savings account funded by a fixed monthly instalment, debited automatically from a bank account you already hold, for a term agreed in advance. Cosmos Bank's own recurring deposit page makes the mechanism explicit: a standing instruction frees the depositor from personally paying the instalment every month.
The defining difference from a pigmy deposit is who does the work. An RD is paid; a pigmy deposit is collected. An RD assumes you already have a bank account with money sitting in it on the due date. A pigmy deposit assumes only that you have cash in hand at the end of a working day, which is why it exists at all for people an RD does not reach.
That difference shows up directly in the rate. At the same institution, an RD typically pays two to three times more than that bank's own pigmy scheme: Canara Bank's recurring deposit is priced off its term-deposit card, 6.25% for five-to-ten-year money, against 2.00% on its Nitya Nidhi Deposit, and Cosmos Bank's term-deposit rate of 7.00% sits well above its 3.00% pigmy rate. The gap is the price of the doorstep collector; an RD has no agent and no commission to pay for.
Deposit insurance treats the two products the same way once the institution is a bank: DICGC's ₹5,00,000-per-depositor cover explicitly includes recurring deposits, at any state, central or primary co-operative bank. It does not extend to an RD-style product at a credit society or Nidhi company, exactly as with a pigmy account.