A Fixed Deposit, or FD, is one of the simplest and most familiar investments in India — you hand over a lumpsum to a bank or post office for a chosen tenure, ranging from a few months to several years, and in return they pay you a fixed, pre-agreed interest rate for the entire period. The interest rate is locked in the day you open the FD and doesn't change even if market rates move up or down later.
FDs are popular because they're simple, widely available, and considered very safe, especially with bank deposits up to ₹5 lakh insured by the DICGC. The trade-off is that FD returns are usually modest and fully taxable as per your income slab, so after adjusting for tax and inflation, the real growth in your money can be quite limited. FDs work best for money you want to keep completely safe and accessible within a known timeframe, rather than for long-term wealth building.