A Fixed Deposit gives you fixed interest on your investment for a fixed time (tenure). There are two issues:
- But you have to pay income tax on the returns each year which drags down compounding of your money.
- The interest rate will likely change when your term is over.
With a cash mutual fund or liquid mutual fund:
- You get an interest which is slightly higher than bank interest.
- Tax is due only when you redeem. This helps in compounding growth.
- If you redeem after 3 years, then tax is much less as your gain is offset against inflation.
Also read more on why banks are like clearing desks and not piggy banks: https://www.jama.co.in/bank-savings-accounts-are-like-working-desks-not-piggy-banks/